The built in e-stop button effectively kills power completely to the controller, you could use an external switch for this as well. I’m sure an internet search would find something appropriate
also - on the breakout board there’s a pin labeled “e-stop” (pin 23) which I would imagine could be used for a soft e-stop although I haven’t tested it.
If you’re going to be using both legs of your 240v circuit make sure you have an appropriate neutral conductor in addition to the 2 “hots” and not using the grounding conductor (bare wire) for the unbalanced load between the 2 legs.