I made this a while ago when I switched from t-track to a threaded insert wasteboard. The t-track came with thumb screw nuts, but in re-using the hex bolts and now screwing in from above, I didn’t want to use a wrench all the time so I made this knob. It’s compact, sufficiently grippy, provides enough force for anything I’ve done, and has a little magnet in the underside to keep it on the hex bolts when you’re re-gripping for the next turn.
Link to cutrocket if you want to make it. It’s been going strong for maybe a year now with minimal wear and still works great!