Need assistance with electric enclosure please (CSMIO/AC Contactor issue)

[JAZZCNC]

also I would like to you utilise the software to enable a power on signal

If your refereing to HV enable then it's not really very suited to this application because it will Kill power to VFD every time you put Mach in reset. Which will be often. This constant stop starting isn't good for the Vfd and will damage it over time.
Also you won't be able to start cutting straight away after a reset and will need to wait for VFD to power up fully which could be pain.

If you really do want the VFD turned off then I would have the VFD tied to E-stop but keep it separate from HV enable. Just have HV enable control the drives PSU and the Spindle RUN Command.
This way when Mach3 is in Reset mode then the VFD stays on but can't started until mach is reset. At which point HV enable turns on the drives and allows spindle RUN signal to reach VFD when needed.

Think of it has two separate systems working together. E-stop is hardwired and kills everything, HV enable just kills Drives and Run etc but only when mach is in Reset.
There are many times you'll want some things powered while Mach is in Reset mode. Ie Vacume but at same time your not in E-stop condition.