Derek,
Dumb, naa. If you think about it why not stop the spindle for a 'feed hold' on a lathe. You are stopping the cut - stop the spindle - safety. I believe that Mach3 is probably one of the best thought-out operating systems available - for the rediculously low price for the license. These encounters are all too easy to change for one to complain about dumb...
It would, however, make sense to withdraw the tool on a feedhold or stop. Carbide would appreciate that.
Bill C.