how well do old saves work on the newest update? i don't wanna replay the whole game everytime new content drops. if it's an issue that can't be dealt with, could you maybe add some form debug or cheat menu?
Old saves really break the game with these updates that go and add content to existing stages.
I understand not wanting to start from the beginning again.
My advise would be to wait a year or so between going back to play the game. Then there should be so much new content scattered around the game that playing from the start feels fresh again.
At some point in the future, when the game reaches a beta state, save compatibility between updates will be a thing.