Looks cool. Hope it works out. When I first got my lesche, the handle cover soon slid off so I super glued it and shortly afterwards read a post about putting a rare earth magnet in the handle. Sounds like a good idea but a little late for me now but I may try your idea
Depending on what your looking for could be to eliminate false positives or to aid in finding relics. Don’t have much time in the field yet so it my not have a practical application. Does not seem to effect functionality so worse case I would be picking bunch of stuff off but so far has not been the case.