Certainly wouldn’t prioritize this before key gameplay improvements mentioned in this thead, but I think it’d be cool to have little identifying marks on certain illuvials when they’re not found in their main region. Like if slashing is mainly in the ice regions but you find it in abysmal basin they have a little moss on them or tribal face paint showing they strayed and if you combine them to level up they lose the marks unless you have 3 all with the same marks. Some lore behind it would be fun too.
Depending on the time this would take maybe it’s an easy way to add some shallow lore early on. As mentioned maybe some illuvial tribes strayed from the majority, maybe running from something etc.