My current keyboard is 34 keys split, but I still need to move my right hand away from keyboard to mouse from time to time. I am aware about options that are possible (cirque trackpad, various trackballs and etc.), but I wanted to investigate what can be done with joystick (as it is quite cheap opti...
So I have tried to play around with joystick's algorithms a little bit and made QMK PR in the end.
I haven't started experimenting around with the code for joysticks but am in the middle of making a keyboard (half) with a joystick. Did you find it worked ok just for acting as keyboard keys/combinations of keys?
I see under the 'Accelerated' portion where you tried to emulate mouse keys there weren't really any results?
Unfortunately it's not too well organised, but it just does an analogReadPin to get an X/Y value, scales it to the desired mouse values, and sends it using a pointing_device_task.
I am a big fan of joystick pointing devices, would love to see what you end up making!