I think this is honestly a big one, I saw you guys support key mapping on your own controllers why not add this to 3rd party controllers? I get it you want to sell your controllers to the mass and give people a reason to purchase them over cheaper alternatives but I simply don't like the layout of the controllers you guys are offering. I couldn't find a single controller that is more comfortable and perfect for my hands than my Ipega 9023. Adding that feature into your overlay would be a HUGE deal as people without root are usually stuck using highly sus software like the octopus overlay which is borderline just installing spyware on your phone.
@Gustav_ASUS sorry to bother you but did you get something back from the team yet? I believe the addition of ipega or any other bluetooth controller should be relatively simple as there are many open source programs out there that do utilize the ipega controllers for the same feature albeit they require root to do so.