Comments sought on new build: A CNC Router for RC Gliders and Planes

[JAZZCNC]

I don't include Limits in E-stop Circuit any more as they are not really an Emergency situation but rather a positional error. Instead I have them Halt the control/software and Disable the drives using Enable.

Regards Stopping the VFD then if your talking as part of E-stop Circuit then I use Timer Relay along with an E-stop signal using relay contact.
E-stop signal tells VFD to Stop spindle and then few seconds later when comes to stop Timer relay removes power.! . . .BUT . . . In all honesty for a DIY enviroment then just stopping the VFD spinning is enough.

Never rely on Mach3 or any software to shut anything down that can hurt you. Do it your self with relays etc then just send software a signal to let know you have shut it down. In your case IP-M will shut it down for you by disabeling the outputs when E-stop occurs but again don't trust it and put another defence in place and then still send Mach3 signal.

Yes I only Remove 24V to Master relay or in your case Pilz.