IT IS A HANDLE, it does nothing but operate the clamping mechanism, grind it , hack saw it or hit the threads with a hammer and deform them so that it stays where you want it, non-problem solved.Has anybody thought about putting a small jamb nut onto the handle shaft before screwing it in? Then you simply screw the handle in as far as it will gotten lock it there with the nut... this will shorten the depth you go in and prevent any tendency for the handle to loosen. That's what I would do, anyway.
Froggie