There is a thing called developer settings which each phone has a specific combination to unlock (it is not a jailbreak or hack), and from there you can set the default mode the phone is entering when connected to USB. I’ll try it later on my phone, this sounds like fun!
EDIT: It looks like Ksoloti recognizes my phone now instantly. I have no MIDI app right now but it should work!
This is how it should look like:
This might just be a great way to recycle old phones and tablets.