core: skip importing blocks that below finalized height

core/blockchain.go

@@ -1938,6 +1938,16 @@ func (bc *BlockChain) insertChain(chain types.Blocks, setHead bool) (int, error)
 		}
 		// Falls through to the block import
 	}
+
+	// Left-trim all the blocks that below finalized height
+	if posa, ok := bc.Engine().(consensus.PoSA); ok {
+		if finalizedHeader := posa.GetFinalizedHeader(bc, bc.CurrentBlock()); finalizedHeader != nil {
+			for block != nil && block.NumberU64() <= finalizedHeader.Number.Uint64() {
+				block, err = it.next()
+			}
+		}
+	}
+
 	switch {
 	// First block is pruned
 	case errors.Is(err, consensus.ErrPrunedAncestor):