Use fork choice to ensure that the execution envelope snapshot is populated in most cases

consensus/fork_choice/src/fork_choice.rs

@@ -1565,6 +1565,22 @@ where
         }
     }
 
+    /// Returns the latest ancestor of `block_root` whose `PayloadStatus` is `Full`.
+    pub fn latest_parent_full_block(
+        &self,
+        block_root: Hash256,
+        spec: &ChainSpec,
+    ) -> Result<Option<Hash256>, Error<T::Error>> {
+        if self.is_finalized_checkpoint_or_descendant(block_root) {
+            let proposer_boost_root = self.fc_store.proposer_boost_root();
+            self.proto_array
+                .latest_parent_full_block::<E>(block_root, proposer_boost_root, spec)
+                .map_err(Error::ProtoArrayError)
+        } else {
+            Err(Error::DoesNotDescendFromFinalizedCheckpoint)
+        }
+    }
+
     /// Returns the canonical payload status of a block. See
     /// `ProtoArrayForkChoice::get_canonical_payload_status`.
     pub fn get_canonical_payload_status(