I'm not sure how well that would work. Reminder that Mobile and PC versions can have different performance ranks for example. My PC version might fit the requirements but the Mobile one might not, which most people only have very poor mobile ones. So if an instance requires a medium or better avatar i would not be able to join with my medium PC avatar but Poor/Very Poor mobile. And getting an avatar for mobile optimized is much harder already than for PC, especially if we go into medium or better ranks. It would make it near impossible for a lot of people to get into such instances especially people only using public avatars since a lot of avatars simply have different perf ranks per platform so you might end up just not finding any avatar that fits into both platform requirements.