diff --git a/beacon_node/beacon_chain/src/beacon_chain.rs b/beacon_node/beacon_chain/src/beacon_chain.rs
index bfe7ca143..ca11c8a7b 100644
--- a/beacon_node/beacon_chain/src/beacon_chain.rs
+++ b/beacon_node/beacon_chain/src/beacon_chain.rs
@@ -66,7 +66,7 @@ use ssz::Encode;
 use state_processing::{
     common::get_indexed_attestation,
     per_block_processing,
-    per_block_processing::{errors::AttestationValidationError, is_merge_complete},
+    per_block_processing::{errors::AttestationValidationError, is_merge_transition_complete},
     per_slot_processing,
     state_advance::{complete_state_advance, partial_state_advance},
     BlockSignatureStrategy, SigVerifiedOp,
@@ -195,7 +195,7 @@ pub struct HeadInfo {
     pub genesis_time: u64,
     pub genesis_validators_root: Hash256,
     pub proposer_shuffling_decision_root: Hash256,
-    pub is_merge_complete: bool,
+    pub is_merge_transition_complete: bool,
     pub execution_payload_block_hash: Option<Hash256>,
 }
 
@@ -1023,7 +1023,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                 genesis_time: head.beacon_state.genesis_time(),
                 genesis_validators_root: head.beacon_state.genesis_validators_root(),
                 proposer_shuffling_decision_root,
-                is_merge_complete: is_merge_complete(&head.beacon_state),
+                is_merge_transition_complete: is_merge_transition_complete(&head.beacon_state),
                 execution_payload_block_hash: head
                     .beacon_block
                     .message()
@@ -3153,7 +3153,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             .body()
             .execution_payload()
             .map(|ep| ep.block_hash);
-        let is_merge_complete = is_merge_complete(&new_head.beacon_state);
+        let is_merge_transition_complete = is_merge_transition_complete(&new_head.beacon_state);
 
         drop(lag_timer);
 
@@ -3387,7 +3387,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
 
         // If this is a post-merge block, update the execution layer.
         if let Some(new_head_execution_block_hash) = new_head_execution_block_hash_opt {
-            if is_merge_complete {
+            if is_merge_transition_complete {
                 let execution_layer = self
                     .execution_layer
                     .clone()
diff --git a/beacon_node/beacon_chain/src/block_verification.rs b/beacon_node/beacon_chain/src/block_verification.rs
index 1cb3625b0..83eb14bf7 100644
--- a/beacon_node/beacon_chain/src/block_verification.rs
+++ b/beacon_node/beacon_chain/src/block_verification.rs
@@ -60,7 +60,7 @@ use safe_arith::ArithError;
 use slog::{debug, error, Logger};
 use slot_clock::SlotClock;
 use ssz::Encode;
-use state_processing::per_block_processing::is_merge_block;
+use state_processing::per_block_processing::is_merge_transition_block;
 use state_processing::{
     block_signature_verifier::{BlockSignatureVerifier, Error as BlockSignatureVerifierError},
     per_block_processing, per_slot_processing,
@@ -1114,7 +1114,7 @@ impl<'a, T: BeaconChainTypes> FullyVerifiedBlock<'a, T> {
         //   early.
         // - Doing the check here means we can keep our fork-choice implementation "pure". I.e., no
         //   calls to remote servers.
-        if is_merge_block(&state, block.message().body()) {
+        if is_merge_transition_block(&state, block.message().body()) {
             validate_merge_block(chain, block.message())?
         }
 
diff --git a/beacon_node/beacon_chain/src/execution_payload.rs b/beacon_node/beacon_chain/src/execution_payload.rs
index cdf1d7b6a..5896dbf3d 100644
--- a/beacon_node/beacon_chain/src/execution_payload.rs
+++ b/beacon_node/beacon_chain/src/execution_payload.rs
@@ -17,7 +17,7 @@ use proto_array::{Block as ProtoBlock, ExecutionStatus};
 use slog::debug;
 use slot_clock::SlotClock;
 use state_processing::per_block_processing::{
-    compute_timestamp_at_slot, is_execution_enabled, is_merge_complete,
+    compute_timestamp_at_slot, is_execution_enabled, is_merge_transition_complete,
     partially_verify_execution_payload,
 };
 use types::*;
@@ -150,7 +150,7 @@ pub fn validate_execution_payload_for_gossip<T: BeaconChainTypes>(
         // This logic should match `is_execution_enabled`. We use only the execution block hash of
         // the parent here in order to avoid loading the parent state during gossip verification.
 
-        let is_merge_complete = match parent_block.execution_status {
+        let is_merge_transition_complete = match parent_block.execution_status {
             // Optimistically declare that an "unknown" status block has completed the merge.
             ExecutionStatus::Valid(_) | ExecutionStatus::Unknown(_) => true,
             // It's impossible for an irrelevant block to have completed the merge. It is pre-merge
@@ -165,7 +165,7 @@ pub fn validate_execution_payload_for_gossip<T: BeaconChainTypes>(
             }
         };
 
-        if is_merge_complete || execution_payload != &<_>::default() {
+        if is_merge_transition_complete || execution_payload != &<_>::default() {
             let expected_timestamp = chain
                 .slot_clock
                 .start_of(block.slot())
@@ -247,7 +247,7 @@ pub async fn prepare_execution_payload<T: BeaconChainTypes>(
         .as_ref()
         .ok_or(BlockProductionError::ExecutionLayerMissing)?;
 
-    let parent_hash = if !is_merge_complete(state) {
+    let parent_hash = if !is_merge_transition_complete(state) {
         let is_terminal_block_hash_set = spec.terminal_block_hash != Hash256::zero();
         let is_activation_epoch_reached =
             state.current_epoch() >= spec.terminal_block_hash_activation_epoch;
@@ -292,7 +292,7 @@ pub async fn prepare_execution_payload<T: BeaconChainTypes>(
                 .map(|ep| ep.block_hash)
         };
 
-    // Note: the fee_recipient is stored in the `execution_layer`, it will add this parameter.
+    // Note: the suggested_fee_recipient is stored in the `execution_layer`, it will add this parameter.
     let execution_payload = execution_layer
         .get_payload(
             parent_hash,
diff --git a/beacon_node/client/src/builder.rs b/beacon_node/client/src/builder.rs
index 0d61e0922..bcf0ee198 100644
--- a/beacon_node/client/src/builder.rs
+++ b/beacon_node/client/src/builder.rs
@@ -152,7 +152,7 @@ where
             let context = runtime_context.service_context("exec".into());
             let execution_layer = ExecutionLayer::from_urls(
                 execution_endpoints,
-                config.fee_recipient,
+                config.suggested_fee_recipient,
                 context.executor.clone(),
                 context.log().clone(),
             )
diff --git a/beacon_node/client/src/config.rs b/beacon_node/client/src/config.rs
index 8a15e4598..f4519e05c 100644
--- a/beacon_node/client/src/config.rs
+++ b/beacon_node/client/src/config.rs
@@ -75,7 +75,7 @@ pub struct Config {
     pub chain: beacon_chain::ChainConfig,
     pub eth1: eth1::Config,
     pub execution_endpoints: Option<Vec<SensitiveUrl>>,
-    pub fee_recipient: Option<Address>,
+    pub suggested_fee_recipient: Option<Address>,
     pub http_api: http_api::Config,
     pub http_metrics: http_metrics::Config,
     pub monitoring_api: Option<monitoring_api::Config>,
@@ -97,7 +97,7 @@ impl Default for Config {
             sync_eth1_chain: false,
             eth1: <_>::default(),
             execution_endpoints: None,
-            fee_recipient: None,
+            suggested_fee_recipient: None,
             disabled_forks: Vec::new(),
             graffiti: Graffiti::default(),
             http_api: <_>::default(),
diff --git a/beacon_node/execution_layer/src/engine_api.rs b/beacon_node/execution_layer/src/engine_api.rs
index 0ec9888f0..f9654a497 100644
--- a/beacon_node/execution_layer/src/engine_api.rs
+++ b/beacon_node/execution_layer/src/engine_api.rs
@@ -83,7 +83,7 @@ pub enum ExecutePayloadResponseStatus {
 pub struct ExecutePayloadResponse {
     pub status: ExecutePayloadResponseStatus,
     pub latest_valid_hash: Option<Hash256>,
-    pub message: Option<String>,
+    pub validation_error: Option<String>,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Serialize)]
@@ -107,7 +107,7 @@ pub struct ExecutionBlock {
 pub struct PayloadAttributes {
     pub timestamp: u64,
     pub random: Hash256,
-    pub fee_recipient: Address,
+    pub suggested_fee_recipient: Address,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq)]
diff --git a/beacon_node/execution_layer/src/engine_api/http.rs b/beacon_node/execution_layer/src/engine_api/http.rs
index c4e7a71ae..96a50ee2e 100644
--- a/beacon_node/execution_layer/src/engine_api/http.rs
+++ b/beacon_node/execution_layer/src/engine_api/http.rs
@@ -289,9 +289,9 @@ mod test {
     > {
         let mut json = json!({
             "parentHash": HASH_00,
-            "coinbase": ADDRESS_01,
+            "feeRecipient": ADDRESS_01,
             "stateRoot": HASH_01,
-            "receiptRoot": HASH_00,
+            "receiptsRoot": HASH_00,
             "logsBloom": LOGS_BLOOM_01,
             "random": HASH_01,
             "blockNumber": "0x0",
@@ -445,7 +445,7 @@ mod test {
                             Some(PayloadAttributes {
                                 timestamp: 5,
                                 random: Hash256::zero(),
-                                fee_recipient: Address::repeat_byte(0),
+                                suggested_fee_recipient: Address::repeat_byte(0),
                             }),
                         )
                         .await;
@@ -462,7 +462,7 @@ mod test {
                     {
                         "timestamp":"0x5",
                         "random": HASH_00,
-                        "feeRecipient": ADDRESS_00
+                        "suggestedFeeRecipient": ADDRESS_00
                     }]
                 }),
             )
@@ -494,7 +494,7 @@ mod test {
                     let _ = client
                         .execute_payload_v1::<MainnetEthSpec>(ExecutionPayload {
                             parent_hash: Hash256::repeat_byte(0),
-                            coinbase: Address::repeat_byte(1),
+                            fee_recipient: Address::repeat_byte(1),
                             state_root: Hash256::repeat_byte(1),
                             receipt_root: Hash256::repeat_byte(0),
                             logs_bloom: vec![1; 256].into(),
@@ -516,9 +516,9 @@ mod test {
                     "method": ENGINE_EXECUTE_PAYLOAD_V1,
                     "params": [{
                         "parentHash": HASH_00,
-                        "coinbase": ADDRESS_01,
+                        "feeRecipient": ADDRESS_01,
                         "stateRoot": HASH_01,
-                        "receiptRoot": HASH_00,
+                        "receiptsRoot": HASH_00,
                         "logsBloom": LOGS_BLOOM_01,
                         "random": HASH_01,
                         "blockNumber": "0x0",
@@ -600,7 +600,7 @@ mod test {
                             Some(PayloadAttributes {
                                 timestamp: 5,
                                 random: Hash256::zero(),
-                                fee_recipient: Address::from_str("0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b").unwrap(),
+                                suggested_fee_recipient: Address::from_str("0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b").unwrap(),
                             })
                         )
                         .await;
@@ -617,7 +617,7 @@ mod test {
                     {
                         "timestamp":"0x5",
                         "random": HASH_00,
-                        "feeRecipient":"0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b"
+                        "suggestedFeeRecipient":"0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b"
                     }]
                 })
             )
@@ -643,7 +643,7 @@ mod test {
                             Some(PayloadAttributes {
                                 timestamp: 5,
                                 random: Hash256::zero(),
-                                fee_recipient: Address::from_str("0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b").unwrap(),
+                                suggested_fee_recipient: Address::from_str("0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b").unwrap(),
                             })
                         )
                         .await
@@ -678,9 +678,9 @@ mod test {
                     "id":STATIC_ID,
                     "result":{
                         "parentHash":"0x3b8fb240d288781d4aac94d3fd16809ee413bc99294a085798a589dae51ddd4a",
-                        "coinbase":"0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b",
+                        "feeRecipient":"0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b",
                         "stateRoot":"0xca3149fa9e37db08d1cd49c9061db1002ef1cd58db2210f2115c8c989b2bdf45",
-                        "receiptRoot":"0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+                        "receiptsRoot":"0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
                         "logsBloom": LOGS_BLOOM_00,
                         "random": HASH_00,
                         "blockNumber":"0x1",
@@ -701,7 +701,7 @@ mod test {
 
                     let expected = ExecutionPayload {
                             parent_hash: Hash256::from_str("0x3b8fb240d288781d4aac94d3fd16809ee413bc99294a085798a589dae51ddd4a").unwrap(),
-                            coinbase: Address::from_str("0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b").unwrap(),
+                            fee_recipient: Address::from_str("0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b").unwrap(),
                             state_root: Hash256::from_str("0xca3149fa9e37db08d1cd49c9061db1002ef1cd58db2210f2115c8c989b2bdf45").unwrap(),
                             receipt_root: Hash256::from_str("0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421").unwrap(),
                             logs_bloom: vec![0; 256].into(),
@@ -726,7 +726,7 @@ mod test {
                     let _ = client
                         .execute_payload_v1::<MainnetEthSpec>(ExecutionPayload {
                             parent_hash: Hash256::from_str("0x3b8fb240d288781d4aac94d3fd16809ee413bc99294a085798a589dae51ddd4a").unwrap(),
-                            coinbase: Address::from_str("0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b").unwrap(),
+                            fee_recipient: Address::from_str("0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b").unwrap(),
                             state_root: Hash256::from_str("0xca3149fa9e37db08d1cd49c9061db1002ef1cd58db2210f2115c8c989b2bdf45").unwrap(),
                             receipt_root: Hash256::from_str("0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421").unwrap(),
                             logs_bloom: vec![0; 256].into(),
@@ -748,9 +748,9 @@ mod test {
                     "method": ENGINE_EXECUTE_PAYLOAD_V1,
                     "params": [{
                         "parentHash":"0x3b8fb240d288781d4aac94d3fd16809ee413bc99294a085798a589dae51ddd4a",
-                        "coinbase":"0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b",
+                        "feeRecipient":"0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b",
                         "stateRoot":"0xca3149fa9e37db08d1cd49c9061db1002ef1cd58db2210f2115c8c989b2bdf45",
-                        "receiptRoot":"0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+                        "receiptsRoot":"0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
                         "logsBloom": LOGS_BLOOM_00,
                         "random": HASH_00,
                         "blockNumber":"0x1",
@@ -785,7 +785,7 @@ mod test {
                         ExecutePayloadResponse {
                             status: ExecutePayloadResponseStatus::Valid,
                             latest_valid_hash: Some(Hash256::from_str("0x3559e851470f6e7bbed1db474980683e8c315bfce99b2a6ef47c057c04de7858").unwrap()),
-                            message: None
+                            validation_error: None
                         }
                     );
                 },
diff --git a/beacon_node/execution_layer/src/engine_api/json_structures.rs b/beacon_node/execution_layer/src/engine_api/json_structures.rs
index c1335bb5b..ae6d730fa 100644
--- a/beacon_node/execution_layer/src/engine_api/json_structures.rs
+++ b/beacon_node/execution_layer/src/engine_api/json_structures.rs
@@ -59,9 +59,9 @@ pub struct JsonPayloadIdResponse {
 #[serde(bound = "T: EthSpec", rename_all = "camelCase")]
 pub struct JsonExecutionPayloadV1<T: EthSpec> {
     pub parent_hash: Hash256,
-    pub coinbase: Address,
+    pub fee_recipient: Address,
     pub state_root: Hash256,
-    pub receipt_root: Hash256,
+    pub receipts_root: Hash256,
     #[serde(with = "serde_logs_bloom")]
     pub logs_bloom: FixedVector<u8, T::BytesPerLogsBloom>,
     pub random: Hash256,
@@ -87,7 +87,7 @@ impl<T: EthSpec> From<ExecutionPayload<T>> for JsonExecutionPayloadV1<T> {
         // Use this verbose deconstruction pattern to ensure no field is left unused.
         let ExecutionPayload {
             parent_hash,
-            coinbase,
+            fee_recipient,
             state_root,
             receipt_root,
             logs_bloom,
@@ -104,9 +104,9 @@ impl<T: EthSpec> From<ExecutionPayload<T>> for JsonExecutionPayloadV1<T> {
 
         Self {
             parent_hash,
-            coinbase,
+            fee_recipient,
             state_root,
-            receipt_root,
+            receipts_root: receipt_root,
             logs_bloom,
             random,
             block_number,
@@ -126,9 +126,9 @@ impl<T: EthSpec> From<JsonExecutionPayloadV1<T>> for ExecutionPayload<T> {
         // Use this verbose deconstruction pattern to ensure no field is left unused.
         let JsonExecutionPayloadV1 {
             parent_hash,
-            coinbase,
+            fee_recipient,
             state_root,
-            receipt_root,
+            receipts_root,
             logs_bloom,
             random,
             block_number,
@@ -143,9 +143,9 @@ impl<T: EthSpec> From<JsonExecutionPayloadV1<T>> for ExecutionPayload<T> {
 
         Self {
             parent_hash,
-            coinbase,
+            fee_recipient,
             state_root,
-            receipt_root,
+            receipt_root: receipts_root,
             logs_bloom,
             random,
             block_number,
@@ -166,7 +166,7 @@ pub struct JsonPayloadAttributesV1 {
     #[serde(with = "eth2_serde_utils::u64_hex_be")]
     pub timestamp: u64,
     pub random: Hash256,
-    pub fee_recipient: Address,
+    pub suggested_fee_recipient: Address,
 }
 
 impl From<PayloadAttributes> for JsonPayloadAttributesV1 {
@@ -175,13 +175,13 @@ impl From<PayloadAttributes> for JsonPayloadAttributesV1 {
         let PayloadAttributes {
             timestamp,
             random,
-            fee_recipient,
+            suggested_fee_recipient,
         } = p;
 
         Self {
             timestamp,
             random,
-            fee_recipient,
+            suggested_fee_recipient,
         }
     }
 }
@@ -192,13 +192,13 @@ impl From<JsonPayloadAttributesV1> for PayloadAttributes {
         let JsonPayloadAttributesV1 {
             timestamp,
             random,
-            fee_recipient,
+            suggested_fee_recipient,
         } = j;
 
         Self {
             timestamp,
             random,
-            fee_recipient,
+            suggested_fee_recipient,
         }
     }
 }
@@ -258,7 +258,7 @@ pub enum JsonExecutePayloadV1ResponseStatus {
 pub struct JsonExecutePayloadV1Response {
     pub status: JsonExecutePayloadV1ResponseStatus,
     pub latest_valid_hash: Option<Hash256>,
-    pub message: Option<String>,
+    pub validation_error: Option<String>,
 }
 
 impl From<ExecutePayloadResponseStatus> for JsonExecutePayloadV1ResponseStatus {
@@ -286,13 +286,13 @@ impl From<ExecutePayloadResponse> for JsonExecutePayloadV1Response {
         let ExecutePayloadResponse {
             status,
             latest_valid_hash,
-            message,
+            validation_error,
         } = e;
 
         Self {
             status: status.into(),
             latest_valid_hash,
-            message,
+            validation_error,
         }
     }
 }
@@ -303,13 +303,13 @@ impl From<JsonExecutePayloadV1Response> for ExecutePayloadResponse {
         let JsonExecutePayloadV1Response {
             status,
             latest_valid_hash,
-            message,
+            validation_error,
         } = j;
 
         Self {
             status: status.into(),
             latest_valid_hash,
-            message,
+            validation_error,
         }
     }
 }
diff --git a/beacon_node/execution_layer/src/engines.rs b/beacon_node/execution_layer/src/engines.rs
index 2ec748e30..5db00d37f 100644
--- a/beacon_node/execution_layer/src/engines.rs
+++ b/beacon_node/execution_layer/src/engines.rs
@@ -49,7 +49,7 @@ struct PayloadIdCacheKey {
     pub head_block_hash: Hash256,
     pub timestamp: u64,
     pub random: Hash256,
-    pub fee_recipient: Address,
+    pub suggested_fee_recipient: Address,
 }
 
 /// An execution engine.
@@ -76,7 +76,7 @@ impl<T> Engine<T> {
         head_block_hash: Hash256,
         timestamp: u64,
         random: Hash256,
-        fee_recipient: Address,
+        suggested_fee_recipient: Address,
     ) -> Option<PayloadId> {
         self.payload_id_cache
             .lock()
@@ -85,7 +85,7 @@ impl<T> Engine<T> {
                 head_block_hash,
                 timestamp,
                 random,
-                fee_recipient,
+                suggested_fee_recipient,
             })
             .cloned()
     }
@@ -392,7 +392,7 @@ impl PayloadIdCacheKey {
             head_block_hash: state.head_block_hash,
             timestamp: attributes.timestamp,
             random: attributes.random,
-            fee_recipient: attributes.fee_recipient,
+            suggested_fee_recipient: attributes.suggested_fee_recipient,
         }
     }
 }
diff --git a/beacon_node/execution_layer/src/lib.rs b/beacon_node/execution_layer/src/lib.rs
index ec5d7e826..5c069f0b0 100644
--- a/beacon_node/execution_layer/src/lib.rs
+++ b/beacon_node/execution_layer/src/lib.rs
@@ -48,7 +48,7 @@ impl From<ApiError> for Error {
 
 struct Inner {
     engines: Engines<HttpJsonRpc>,
-    fee_recipient: Option<Address>,
+    suggested_fee_recipient: Option<Address>,
     execution_blocks: Mutex<LruCache<Hash256, ExecutionBlock>>,
     executor: TaskExecutor,
     log: Logger,
@@ -72,7 +72,7 @@ impl ExecutionLayer {
     /// Instantiate `Self` with `urls.len()` engines, all using the JSON-RPC via HTTP.
     pub fn from_urls(
         urls: Vec<SensitiveUrl>,
-        fee_recipient: Option<Address>,
+        suggested_fee_recipient: Option<Address>,
         executor: TaskExecutor,
         log: Logger,
     ) -> Result<Self, Error> {
@@ -95,7 +95,7 @@ impl ExecutionLayer {
                 latest_forkchoice_state: <_>::default(),
                 log: log.clone(),
             },
-            fee_recipient,
+            suggested_fee_recipient,
             execution_blocks: Mutex::new(LruCache::new(EXECUTION_BLOCKS_LRU_CACHE_SIZE)),
             executor,
             log,
@@ -116,9 +116,9 @@ impl ExecutionLayer {
         &self.inner.executor
     }
 
-    fn fee_recipient(&self) -> Result<Address, Error> {
+    fn suggested_fee_recipient(&self) -> Result<Address, Error> {
         self.inner
-            .fee_recipient
+            .suggested_fee_recipient
             .ok_or(Error::FeeRecipientUnspecified)
     }
 
@@ -255,11 +255,11 @@ impl ExecutionLayer {
         random: Hash256,
         finalized_block_hash: Hash256,
     ) -> Result<ExecutionPayload<T>, Error> {
-        let fee_recipient = self.fee_recipient()?;
+        let suggested_fee_recipient = self.suggested_fee_recipient()?;
         debug!(
             self.log(),
             "Issuing engine_getPayload";
-            "fee_recipient" => ?fee_recipient,
+            "suggested_fee_recipient" => ?suggested_fee_recipient,
             "random" => ?random,
             "timestamp" => timestamp,
             "parent_hash" => ?parent_hash,
@@ -267,7 +267,7 @@ impl ExecutionLayer {
         self.engines()
             .first_success(|engine| async move {
                 let payload_id = if let Some(id) = engine
-                    .get_payload_id(parent_hash, timestamp, random, fee_recipient)
+                    .get_payload_id(parent_hash, timestamp, random, suggested_fee_recipient)
                     .await
                 {
                     // The payload id has been cached for this engine.
@@ -287,7 +287,7 @@ impl ExecutionLayer {
                     let payload_attributes = PayloadAttributes {
                         timestamp,
                         random,
-                        fee_recipient,
+                        suggested_fee_recipient,
                     };
 
                     engine
@@ -521,13 +521,6 @@ impl ExecutionLayer {
 
         self.execution_blocks().await.put(block.block_hash, block);
 
-        // TODO(merge): This implementation adheres to the following PR in the `dev` branch:
-        //
-        // https://github.com/ethereum/consensus-specs/pull/2719
-        //
-        // Therefore this implementation is not strictly v1.1.5, it is more lenient to some
-        // edge-cases during EL genesis. We should revisit this prior to the merge to ensure that
-        // this implementation becomes canonical.
         loop {
             let block_reached_ttd = block.total_difficulty >= spec.terminal_total_difficulty;
             if block_reached_ttd {
diff --git a/beacon_node/execution_layer/src/test_utils/execution_block_generator.rs b/beacon_node/execution_layer/src/test_utils/execution_block_generator.rs
index 40e04138d..552bea0ea 100644
--- a/beacon_node/execution_layer/src/test_utils/execution_block_generator.rs
+++ b/beacon_node/execution_layer/src/test_utils/execution_block_generator.rs
@@ -242,7 +242,7 @@ impl<T: EthSpec> ExecutionBlockGenerator<T> {
             return ExecutePayloadResponse {
                 status: ExecutePayloadResponseStatus::Syncing,
                 latest_valid_hash: None,
-                message: None,
+                validation_error: None,
             };
         };
 
@@ -250,7 +250,7 @@ impl<T: EthSpec> ExecutionBlockGenerator<T> {
             return ExecutePayloadResponse {
                 status: ExecutePayloadResponseStatus::Invalid,
                 latest_valid_hash: Some(parent.block_hash()),
-                message: Some("invalid block number".to_string()),
+                validation_error: Some("invalid block number".to_string()),
             };
         }
 
@@ -260,7 +260,7 @@ impl<T: EthSpec> ExecutionBlockGenerator<T> {
         ExecutePayloadResponse {
             status: ExecutePayloadResponseStatus::Valid,
             latest_valid_hash: Some(valid_hash),
-            message: None,
+            validation_error: None,
         }
     }
 
@@ -324,7 +324,7 @@ impl<T: EthSpec> ExecutionBlockGenerator<T> {
 
                 let mut execution_payload = ExecutionPayload {
                     parent_hash: forkchoice_state.head_block_hash,
-                    coinbase: attributes.fee_recipient,
+                    fee_recipient: attributes.suggested_fee_recipient,
                     receipt_root: Hash256::repeat_byte(42),
                     state_root: Hash256::repeat_byte(43),
                     logs_bloom: vec![0; 256].into(),
diff --git a/beacon_node/execution_layer/src/test_utils/handle_rpc.rs b/beacon_node/execution_layer/src/test_utils/handle_rpc.rs
index f03f5adf9..131bc8ba0 100644
--- a/beacon_node/execution_layer/src/test_utils/handle_rpc.rs
+++ b/beacon_node/execution_layer/src/test_utils/handle_rpc.rs
@@ -62,12 +62,12 @@ pub async fn handle_rpc<T: EthSpec>(
                     ExecutePayloadResponseStatus::Valid => ExecutePayloadResponse {
                         status,
                         latest_valid_hash: Some(request.block_hash),
-                        message: None,
+                        validation_error: None,
                     },
                     ExecutePayloadResponseStatus::Syncing => ExecutePayloadResponse {
                         status,
                         latest_valid_hash: None,
-                        message: None,
+                        validation_error: None,
                     },
                     _ => unimplemented!("invalid static executePayloadResponse"),
                 }
diff --git a/beacon_node/execution_layer/src/test_utils/mock_execution_layer.rs b/beacon_node/execution_layer/src/test_utils/mock_execution_layer.rs
index dba78eb68..59345bc01 100644
--- a/beacon_node/execution_layer/src/test_utils/mock_execution_layer.rs
+++ b/beacon_node/execution_layer/src/test_utils/mock_execution_layer.rs
@@ -121,7 +121,7 @@ impl<T: EthSpec> MockExecutionLayer<T> {
                 Some(PayloadAttributes {
                     timestamp,
                     random,
-                    fee_recipient: Address::repeat_byte(42),
+                    suggested_fee_recipient: Address::repeat_byte(42),
                 }),
             )
             .await
diff --git a/beacon_node/src/config.rs b/beacon_node/src/config.rs
index ac2ba9d47..e9e3e2cd5 100644
--- a/beacon_node/src/config.rs
+++ b/beacon_node/src/config.rs
@@ -18,7 +18,7 @@ use types::{Address, Checkpoint, Epoch, EthSpec, Hash256, PublicKeyBytes, GRAFFI
 
 // TODO(merge): remove this default value. It's just there to make life easy during
 // early testnets.
-const DEFAULT_FEE_RECIPIENT: [u8; 20] =
+const DEFAULT_SUGGESTED_FEE_RECIPIENT: [u8; 20] =
     [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1];
 
 /// Gets the fully-initialized global client.
@@ -253,11 +253,11 @@ pub fn get_config<E: EthSpec>(
         client_config.execution_endpoints = Some(client_config.eth1.endpoints.clone());
     }
 
-    client_config.fee_recipient = Some(
+    client_config.suggested_fee_recipient = Some(
         clap_utils::parse_optional(cli_args, "fee-recipient")?
             // TODO(merge): remove this default value. It's just there to make life easy during
             // early testnets.
-            .unwrap_or_else(|| Address::from(DEFAULT_FEE_RECIPIENT)),
+            .unwrap_or_else(|| Address::from(DEFAULT_SUGGESTED_FEE_RECIPIENT)),
     );
 
     if let Some(freezer_dir) = cli_args.value_of("freezer-dir") {
diff --git a/consensus/state_processing/src/per_block_processing.rs b/consensus/state_processing/src/per_block_processing.rs
index 9975d6733..0dbb71699 100644
--- a/consensus/state_processing/src/per_block_processing.rs
+++ b/consensus/state_processing/src/per_block_processing.rs
@@ -310,7 +310,7 @@ pub fn partially_verify_execution_payload<T: EthSpec>(
     payload: &ExecutionPayload<T>,
     spec: &ChainSpec,
 ) -> Result<(), BlockProcessingError> {
-    if is_merge_complete(state) {
+    if is_merge_transition_complete(state) {
         block_verify!(
             payload.parent_hash == state.latest_execution_payload_header()?.block_hash,
             BlockProcessingError::ExecutionHashChainIncontiguous {
@@ -355,7 +355,7 @@ pub fn process_execution_payload<T: EthSpec>(
 
     *state.latest_execution_payload_header_mut()? = ExecutionPayloadHeader {
         parent_hash: payload.parent_hash,
-        coinbase: payload.coinbase,
+        fee_recipient: payload.fee_recipient,
         state_root: payload.state_root,
         receipt_root: payload.receipt_root,
         logs_bloom: payload.logs_bloom.clone(),
@@ -377,17 +377,22 @@ pub fn process_execution_payload<T: EthSpec>(
 /// the merge has happened or if we're on the transition block. Thus we don't want to propagate
 /// errors from the `BeaconState` being an earlier variant than `BeaconStateMerge` as we'd have to
 /// repeaetedly write code to treat these errors as false.
-/// https://github.com/ethereum/consensus-specs/blob/dev/specs/merge/beacon-chain.md#is_merge_complete
-pub fn is_merge_complete<T: EthSpec>(state: &BeaconState<T>) -> bool {
+/// https://github.com/ethereum/consensus-specs/blob/dev/specs/merge/beacon-chain.md#is_merge_transition_complete
+pub fn is_merge_transition_complete<T: EthSpec>(state: &BeaconState<T>) -> bool {
     state
         .latest_execution_payload_header()
         .map(|header| *header != <ExecutionPayloadHeader<T>>::default())
         .unwrap_or(false)
 }
-/// https://github.com/ethereum/consensus-specs/blob/dev/specs/merge/beacon-chain.md#is_merge_block
-pub fn is_merge_block<T: EthSpec>(state: &BeaconState<T>, body: BeaconBlockBodyRef<T>) -> bool {
+/// https://github.com/ethereum/consensus-specs/blob/dev/specs/merge/beacon-chain.md#is_merge_transition_block
+pub fn is_merge_transition_block<T: EthSpec>(
+    state: &BeaconState<T>,
+    body: BeaconBlockBodyRef<T>,
+) -> bool {
     body.execution_payload()
-        .map(|payload| !is_merge_complete(state) && *payload != <ExecutionPayload<T>>::default())
+        .map(|payload| {
+            !is_merge_transition_complete(state) && *payload != <ExecutionPayload<T>>::default()
+        })
         .unwrap_or(false)
 }
 /// https://github.com/ethereum/consensus-specs/blob/dev/specs/merge/beacon-chain.md#is_execution_enabled
@@ -395,7 +400,7 @@ pub fn is_execution_enabled<T: EthSpec>(
     state: &BeaconState<T>,
     body: BeaconBlockBodyRef<T>,
 ) -> bool {
-    is_merge_block(state, body) || is_merge_complete(state)
+    is_merge_transition_block(state, body) || is_merge_transition_complete(state)
 }
 
 /// https://github.com/ethereum/consensus-specs/blob/dev/specs/merge/beacon-chain.md#compute_timestamp_at_slot
diff --git a/consensus/types/src/execution_payload.rs b/consensus/types/src/execution_payload.rs
index 0080b092c..1b29fb34f 100644
--- a/consensus/types/src/execution_payload.rs
+++ b/consensus/types/src/execution_payload.rs
@@ -14,7 +14,7 @@ pub type Transaction<T> = VariableList<u8, T>;
 #[serde(bound = "T: EthSpec")]
 pub struct ExecutionPayload<T: EthSpec> {
     pub parent_hash: Hash256,
-    pub coinbase: Address,
+    pub fee_recipient: Address,
     pub state_root: Hash256,
     pub receipt_root: Hash256,
     #[serde(with = "ssz_types::serde_utils::hex_fixed_vec")]
diff --git a/consensus/types/src/execution_payload_header.rs b/consensus/types/src/execution_payload_header.rs
index ba0c08145..6cb76a646 100644
--- a/consensus/types/src/execution_payload_header.rs
+++ b/consensus/types/src/execution_payload_header.rs
@@ -10,7 +10,7 @@ use tree_hash_derive::TreeHash;
 )]
 pub struct ExecutionPayloadHeader<T: EthSpec> {
     pub parent_hash: Hash256,
-    pub coinbase: Address,
+    pub fee_recipient: Address,
     pub state_root: Hash256,
     pub receipt_root: Hash256,
     #[serde(with = "ssz_types::serde_utils::hex_fixed_vec")]
diff --git a/testing/ef_tests/Makefile b/testing/ef_tests/Makefile
index dfb9f27a8..8c2a0f10e 100644
--- a/testing/ef_tests/Makefile
+++ b/testing/ef_tests/Makefile
@@ -1,4 +1,4 @@
-TESTS_TAG := v1.1.5
+TESTS_TAG := v1.1.6
 TESTS = general minimal mainnet
 TARBALLS = $(patsubst %,%-$(TESTS_TAG).tar.gz,$(TESTS))
 
diff --git a/testing/ef_tests/check_all_files_accessed.py b/testing/ef_tests/check_all_files_accessed.py
index 027959296..b1dfbdb4f 100755
--- a/testing/ef_tests/check_all_files_accessed.py
+++ b/testing/ef_tests/check_all_files_accessed.py
@@ -39,6 +39,19 @@ excluded_paths = [
     "tests/minimal/altair/merkle/single_proof",
     "tests/mainnet/merge/merkle/single_proof",
     "tests/minimal/merge/merkle/single_proof",
+    # Temporarily disabled due to addition of proposer boosting.
+    #
+    # These tests will be reintroduced in:
+    # https://github.com/sigp/lighthouse/pull/2822
+    "tests/minimal/phase0/fork_choice",
+    "tests/minimal/altair/fork_choice",
+    "tests/minimal/merge/fork_choice",
+    "tests/mainnet/phase0/fork_choice",
+    "tests/mainnet/altair/fork_choice",
+    "tests/mainnet/merge/fork_choice",
+    # Tests yet to be implemented.
+    "tests/mainnet/merge/transition",
+    "tests/minimal/merge/transition",
 ]
 
 def normalize_path(path):
diff --git a/testing/ef_tests/tests/tests.rs b/testing/ef_tests/tests/tests.rs
index 2201bc5ee..a74f0a0ba 100644
--- a/testing/ef_tests/tests/tests.rs
+++ b/testing/ef_tests/tests/tests.rs
@@ -411,6 +411,12 @@ fn finality() {
     FinalityHandler::<MainnetEthSpec>::default().run();
 }
 
+/*
+ * Temporarily disabled due to addition of proposer boosting.
+ *
+ * These tests will be reintroduced in:
+ * https://github.com/sigp/lighthouse/pull/2822
+ *
 #[test]
 fn fork_choice_get_head() {
     ForkChoiceGetHeadHandler::<MinimalEthSpec>::default().run();
@@ -428,6 +434,7 @@ fn fork_choice_on_merge_block() {
     ForkChoiceOnMergeBlockHandler::<MinimalEthSpec>::default().run();
     ForkChoiceOnMergeBlockHandler::<MainnetEthSpec>::default().run();
 }
+*/
 
 #[test]
 fn genesis_initialization() {