Request: Android App that Can Use Bluetooth Game Controller as a Keyboard (Maybe Chorded)

This has been on my bucket list for a while: I'd love to have a non-keyboard form of text entry that I can use on the go without a table or stable place to put things down. I just grab a bluetooth game controller for a few bucks, get something to hold the phone on it, and write from anywhere.

If it has a complex entry system that takes time to learn and would make me feel like Neo, even better.

People do sell these weird contraptions (https://www.mytwiddler.com/ and https://shop.tapwithus.com/) that you can hold in one hand to type with, but engineering and manufacturing them at such small scales is pretty damn expensive; over $200 last I looked into it. And I definitely don´t want to learn an input method that is determined entirely by a private company that could become enshittified or go out of business.

Bluetooth game controllers come in a variety of price points and have a stable form factor, so it's definitely a good option here.

Joytokey could be used as a base, but I think it is mostly made for quick gaming shortcuts and would´t be really efficient for exclusive text entry (?). Joytochord, which turns the controller into a chording keyboard, seems to be defunct.

FOSS to the rescue?