I agree about various self-reversing tap heads; for big round/ box column drills. Overall length too bothersome in milling machines to suit me.
There I use a 5/8" shank Hardinge TT Tap Driver. When quill stop lets the tap turn another .070 or so of depth, the clutch disengages, and signals operator to reverse spindle. Very compact, about same as a drill chuck. And works just as well in lathes. And I never power tap in drill chucks.