System for transferring sprites across link connection for hack-to-hack linking
Would this be useful though? Sure, it's definitely a cool idea, but while trading here is basically moot (unless you want to download base data to flash memory? No idea how much space that would take up), isn't it the same with battles too since a different hack would almost certainly also mean differences in the battle engine? Pokémon changes, at the very least, and possibly more involved ones.
This would just be for player sprites.
And with Pokémon changes, stats aren’t recalculated during link battles so base stat changes would correctly be read by the unchanged game