The only way of powering off the snapmaker machine is by turning off the button on the power module. I don't know if this makes any damage to the software, to instantly power off the machine, it couldn't have time to save some configs and things.
I don't know if it's necesari but my suggestion is to add a new power off button in the touchscreen interface so we can click to stop the software and the machine powers off safely and then we click the power off button on the power module.