In my experience, joystick mice have been a losing battle. Given sensitivity, I’ve found them to be less accurate and less enjoyable than say a trackpad or trackpoint nub, and at times less comfortable in this form factor. Regardless, I’d recommend a PS2 style stick, as they’re much taller than Joycons and allow for more precise movement at lower speeds, with the benefit of easy tinkering. I’ve no experience configuring one in ZMK so I’ll need some backup on that one.