Hi Art . I was busy too , with my garden and flower greenhouse (think is right word for).
You right , i didn't think how easy can be . Always was a issue when some error's occur
and Estop fail in time of cutting something in one line or even on engrave , was impossible
to switch to MIDI run M3 and back to default stored fail point .
That simple " button" seem to be the best and easy solution to that.
Buttons are for Cut/engrave, M3, compressor&exhaust , and red laser XY lines for piece alignment
on laser table.
Thank's many beers commin'