M291 non-blocking UNTIL user input?

[theolodian]

We would like to run a process cycle in a loop. I would like the user to be able to cancel the process without hitting the emergency stop. This doesn't seem to be an option with M291? Is the only option to set up an external button? Or is it some complicated thing of setting up a daemon and a button on the user interface?

I was thinking M291 non blocking (or a 'while' with a pop-up) that stays up indefinitely, but if the user presses cancel THEN it breaks the loop at the start of the next cycle. Suggestions? Cheers.