This modification aims to synchronize the transaction's validity with the specific block height, thereby ensuring that each coinbase transaction is uniquely tied to a particular block. To support this mechanism effectively, it becomes crucial to adjust the nSequence field of the coinbase input to SEQUENCE_FINAL. This adjustment is essential because without setting the nSequence to its final value, the coinbase transaction would not pass the IsFinalTx() validation. The validation process checks whether a transaction meets the criteria for being considered final and valid for inclusion in the next block. By mandating these changes, the proposal seeks to fortify the transaction process against potential issues by leveraging the locktime and sequence fields to enforce transaction integrity at a block level.