Ding Ding Ding!!! I think we may have a winner. I like the magnetic switch idea for several reasons. 1st, you already have them. 2nd, you already have them.
B, probably easier to mount and adjust and make "repeatable" or reliable. Wired as a safety switch(es) incorporating a relay to cut main seems easiest. But.... We don't do things because they are easy now do we? No. We only resort to that after we screw up the more complex method and this is our last option to salvage what was a perfectly fine machine to begin with.
I would prefer the monitor switch approach myself but that probably means Comancheizing a brand new winch just to do exploratory surgery to see if it is possible. Of coarse it is possible, you just gotta want it bad enough. I do like the idea of mounting to the bed frame and rails. Are those switches spdt or spst? I guess you can manage that with the relay.
Well, I think I have done enough damage here. Have a great weekend Don. I'll check in with you later.
McDave