AFAIK, it's not clear how much difference in wear a series of writes cause when compared to writes and erases. I do know that very old flash firmwares applied

AFAIK, it's not clear how much difference in wear a series of writes cause when compared to writes and erases. I do know that very old flash firmwares applied that idea, and that new flash evolved in a direction where the wear caused by an erase is closer to the one caused by a write. If modern firmwares do not use it, it's probably because there isn't a lot to gain.