There's a lot of nuance to sending unsplit coins. One further nuance highlighted today is that a sent BCH transaction that is valid on the BSV network will go into the non-final mempool. The user if they have some technical skill, in theory, can replace the transactions with final versions if they act quickly.
Historically there's some imagined miner conspiracy where miners can reorg other miners blocks to get the high fees from certain mined transactions. In order to prevent this, wallets like