I will be back (I will try) :)

Or maybe you can download mods that allows you to save your save data with a hacked Nintendo switch, but you can't play to a 1.2.1 save data in 1.2.0, 1.1.2, 1.1.1, 1.1.0, 1.0.0.

@Epicrafter292 no, it's zfg's one

I think that you can't

Maybe if you take nintendo switch online there is a save in the cloud and then if you come back on the recents versions you can download your save and play (that's a supposition)

gg