Although a lot of people do not know this, DMD2 is not a profitable app.
Which is fine for us, we never looked at it as a finished, commercially ready product.
BUT, it will soon be, on the next big update with new UI and many new things.
What allows us to keep investing on this app is deals with OEMs, like AJP, Fantic, CARPE.
Specially CARPE because we sell the controllers and the profit from the sales allows us to keep our business running and having developers 8h / day working on DMD2.
For this reason DMD2 will not allow you to use any other controller unless it is a CARPE controller.
Maybe in the future when DMD2 matures and becomes a sustainable app we can allow and support other controllers.