That would require installing PowerCLI on all the test VMs?
Yes, if you want to run such a script, you will need the PowerCLI framework to be present.
That's getting quite involved.
I'll need to check after the Easter Bank Holiday weekend now, but hopefully the test VMs have the framework in place, but I suspect they don't.
If you don't have PowerCLI on those target stations, you can still run a script in the guest OS.
You just need to think of another kind of semaphore to pass to the monitoring station.