That is a really cool idea, take that from somebody that often has to do field installs or upgrades. It might be even nicer if you could also use it as a drill guide. In any event there seems to be a range of taps where you need the help of a tool like this. For larger holes I often resort to a large slow speed Milwaukee drill. This doesn't work as well for small taps or where the risk from a broken tap is too great.

The thing that threw me when first looking at this is that the structure looked like an aluminum casting. Your powder coating did a nice job of making me think aluminum. All in all a really nice idea that might even have me ordering a couple of those switching magnets.