Ender 3 Pro bed level wrench / thumbwheel

This is the smallest factor I could do while still being easy to use.

You can use it as a "wrench" - just replace the standard bed level knobs with M4 nuts, slide this wrench over and tighten it.

Alternatively you can glue the nuts to this and leave it in there given it's small enough so that it won't crash into the stepper motor (if like me you have press fit pulleys and had to print an adapter to install dampers)