Converting a working mill configuration to an equivalent sim

Now that I've tightened up my estop game, I can no longer simply turn off my stepper drivers in order to run simulations on my mill software, since doing so makes everything else think there's a fault.  I knew this would happen, but I promised myself I'd figure out how to use a sim instead.

What's the easiest way to copy a mill configuration, and turn the hardware-aware parts into a simulation?  I'd like to preserve as much of my UI (including pyvcp panel) as possible, even if much is non-functional.

(If that's hard, I'll settle for a recommendation on the most functional x/y/z sim to use, instead.)

Can you run the drivers with the motors disconnected (turn the power off before disconnecting the motor)?

Don't make a separate simulation, you might end up with slight differences, which will wreak havoc!

I don't want to start disconnecting hardware for this. It's really just to see, while I'm sitting in my living room, whether the g-code is "mill ready".

In the end, I just took a copy of /usr/share/doc/linuxcnc/examples/sample-configs/sim/axis/axis.ini , and I'm using that. I have a pretty basic mill. I had to adjust the limits in the .ini file, and I realized that since I'm simularing I could bump the velocities way up, and it's been useful, so far.

What kinds of things are you worrying about, that will "wreak havoc"?

Like what if your smulation is catually different than the real-world machne and in real life, the machine ends up being destroyed due to a 1mm difference or something.