I’ve got nearly a decade on you and I can tell you that that enjoyment doesn’t go away. 
When I first got my Glowforge I pushed the button in the middle of a job. Actually, my cat pushed it first. But then I wasn’t sure if he actually pushed it, so I pushed it on purpose to make sure the button doesn’t stop a job. And every once in a while I still push the button in the middle of a job and imagine it’s a turbo button to make the job finish faster. 
It is. But the secret is you have to make the corresponding noise for the speaker to receive the command. That’s what @scott.wiederhold told me in private.
I have those on my X-Carve (on the X-Controller) and made my own version that in inline with my pull down cords in my shop…
I have had several occasions where I saw a print not doing what I expected and raised the lid a half inch for an instant to cancel the print.
The only emergency I can think of in the laser is fire. If that’s the case, ignition has already occurred and pushing a button to kill the power would be an extra step in solving that problem. To put the fire out you have to open the lid, so having the interlocks to kill the power is ideal.
If your laser is on fire a little smoke is the least of your problems.
Edit- a kill switch would also leave the head parked over the fire, killing the print by cracking the lid immediately withdraws the head and parks it in the corner.
Right? Just turned 59 and it’s still there.
We’re all on the same page! 
I like the idea of a distinct E-Stop, though - a big red button wired up to shut down the printer, stuck on the wall where cats and kids won’t hit it. Given the way the Pro is wired, do we need an E-Stop for switching “mains” power, or just a control voltage switch?
If you want a true panic button I’d get one from someone like Rockler and it will cut all power. You could wire this to the filter as well if you are getting one.
Was it ever determined just what functions are halted when that safety plug is pulled out on the back of the Pro? Maybe a mechanical push-button mechanism could be designed to physically pull that little plug?
I think the Pro has a cutoff build into the power supply, controlled by a clip you can pull out. I’m thinking of replacing the clip with a big shiny red switch, so shutting the GF off is super-obvious. Reaching over the GF to reach the power switch might not be fun in the event of a fire. And the plug is behind the printer. 
Can we just take the word “emergency” out of the original request so this isn’t completely derailed by the discussion of e-stops?
The button should pause or abort the job. It’s a perfectly reasonable and convenient thing to do. I’ve wanted it numerous times. It’s sitting there uselessly while the machine is running, so it should do what most people would expect it to do.
I don’t want the functionality of my machine reduced because someone else owns a cat that they let jump on the machine. How about an option in the settings where you can disable the pause function, or even choose whether the button is pause or cancel? Personally I’d like pause by default, hold it down for a few seconds to cancel.
I agree, it should pause (assuming resume is trivial). If some users don’t want that to occur, that’s fine, it should simply be an option users can enable or disable.
Everybody has an equal chance of suggesting something nobody else wants.
One person, one non-binding vote.
I just tested it. If it’s unplugged before you start printing, it does all the scanning and processing and looks like it’s about to let you start, and then pops up a generic error message. If you’re in the middle of a print and disconnect it, it cancels the print and returns home with no message, as if you had clicked the cancel button. That explains why a few people have had mysterious prints that cancel themselves in the middle. Loose staple. P.S. for @rpegg: mine is in there pretty tight, it’s not going to fall out on its own.
If you have a high tolerance for boredom, it’s all here.
Or if you’ve got an extra fan in your exhaust line you can get one of the ones where hitting the off paddle turns off the main outlet but lets the fan run for another 30 seconds (I use them on panel saws, etc so a vacuum attached can clear the hoses of sawdust when shutting down). Then you’d get the extended run time of the exhaust that might help clear things - under normal mode that’s good but in an emergency not sure you want to keep sucking air into it although opening the lid is going to flood it with air anyway.
I like the idea of pressing the button pausing the job, assuming that pressing it again resumes it.
The button is way too easy to press accidentally (it’s huge, lit up, and sticks up) for it to potentially abort a several-hour job. Aborting a job should be hard to do, so it’s only done when people really mean it. Like hitting a big red button that’s mounted on the wall (i.e. an E-Stop), or doing something unusual like holding it down for a long time, or tapping a pattern. Probably with a color change involved, just to make it even more obvious.
Definitely oughta be a sequence of “Dot, dot, dot. Dash, dash, dash. Dot, dot, dot.”
Definitely oughta be a sequence of “Dot, dot, dot. Dash, dash, dash. Dot, dot, dot.”
Brilliant!
Thank you for your suggestion! I’ll pass this on to the team.
By the way, regarding the magic staple- it’s electrical, not mechanical, so you can indeed replace it with a switch. Might be a good topic for a new thread.