Can you discover ANY custom game controller on your app?

If we have a custom ble microcontroller that has a HID service/controller profile, can that be paired from within or outside of the app ? Or must it be MFi certified? We only wish to use the controller for the app, not support other apps for the iPhone.

We're originally trying to have it use a mouse profile, but it appears that isn't supported?
Can you discover ANY custom game controller on your app?
 
 
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