Can I change story mode choices made in KOTFE / KOTET by replaying?
Solution 1:
No, replays do not affect the decisions you made the first time around. Ostensibly, this is because even a small change could invalidate the whole tree of later decisions, and they have not spent the time to add an option that would completely wipe out everything you did later. I'd suspect this is something of a user experience decision too since there are undoubtedly people who would ignore any warnings and reset, and then regret it.
So if you want to make different decisions "for real", you have to create a new character.