Here is an offical response in another thread:
We would love for that to be possible in FireControl but unfortunately all of the motion control firmware is loaded onto the microprocessors on the board inside the electronics enclosure.
I can’t say I have used a lot of PC based controllers, but the one I have used does allow simulation without a connection to the machine. Hopefully future versions will.
If you have network connection between the two machines you could always remote desktop into the one attached to the Pro.