See it would be useful to make an exploit for a game that is free or readily available, unlike fe fates which still goes for $40. But even then, those would be simple userland. Most devs usually (and should) focus on kernelhax rather then userland and secondary.
But that aside, the fact that it uses ext data doesn't really affect how its hacked. Cause i mean, pokemon oras is a mainseries, so you wouldnt think they would skip out costs on anti-cheat programming. In fact, only gen hax AFAIK uses ext data to load stuffs.