2D not an option at this time. Best to use a machine that can handle the workload Might run better on Windows with the same hardware (Better GPU drivers, depending on what GPU it has, still today linux GPU drivers can sometimes be a source of frustration)
How do you add a e-stop button to the Grbl settings if you are using a Arduino uno board with openbuild firmware. Where do you terminate the button to
If it is truly for an emergency, place the E-stop on the main power to your machine so if a true emergency happens, all power is cut. I have used this on both my CNC Lathe and my CNC Router. Amazon.com This is even easer and requires no cutting of power cords for wiring into plugs like the first one. https://www.rockler.com/safety-power-tool-switch. But to answer your question, A0 and Ground, but the two switches I show above are far easier and safer. If a body part is being mangled by the machine, Feed Hold/Abort won't stop it unless you get the router off.
I use both emergency switches. The one that only stops the program from running, the A0 to ground, and the one that cuts off the power to the whole system, the one that Craig linked to Amazon.
Is the config that yall are using is the Openbuild JDs garage and is that IO point a standard for all configs