Hello, looking to sanity check what I'm doing.

Little bit of background, feel free to skip.
I purchased a Chinese CNC router (Forsun if anyone is interested) and I'm pulling out the ncstuido card it came with and replacing it with the massively overkill CMSMIO/IP-S and MPG.

So I've pulled out the dodgy card, avoided touching the 240v side any more than required and added a Meanwell 24v PSU. I have connected up the sensors and tested them, the steppers are connected up but not powered or tested and the spindle is disconnected. My intention is to connect up the MPG module I'm a little unsure when it comes to the estop on that which has now made me question the estop on the rest of the machine.

The machine has a estop and a power button, when plugged in you press the power button which activates a contactor and turns everything on and the estop will cause that to deactivate and turn everything off including the 24v and the IP-S. This seems ok to me so far. For the estop on the MPG, I understand that this would act as a switch for a 24v signal into one of the digital inputs on the IP-S and the IP-S would then use this to trigger a 24v contactor to disable just the spindle and axis motors whilst keeping itself powered on?