Transferring a Moon save into a Sun game?

[nickdos]

Is it possible to transfer a post-credits pokemon Moon save into a pokemon Sun cartridge? Would it break event flags and trainer informaton?

[theSLAYER]

3 minutes ago, nickdos said:

Is it possible to transfer a post-credits pokemon Moon save into a pokemon Sun cartridge? Would it break event flags and trainer informaton?

It could.

I broke the game, and couldn't complete the story,
when I transferred right after getting the flute.

wasn't able to get to the correct altar, for events to continue.