Finally after several tries at calling the Company for tech and getting recordings I went through the back door to repair which gets a live person, who was very happy to connect me to the tech dept
A very helpful tech from Respronics had this answer. I take no responsibility for this info. But for myself I will be trusting since the company in Murray PA that builds the thing should know what it can and cant do. I hope
His answer " As long as the generator in question is putting out sufficient amps watts and volts, and puts out a modified sine wave or better the PR 560 auto with heated hose 550 etc WILL run perfectly fine with no damage to power brick or machine, plugged directly into the 120v AC outlet."
Myself I will add a simple surge protector the same as I have for the power company surges.
That is straight from Respironics tech dept in Murray PA 5 min ago tech name was Adam.
As I said I will be trusting what the company says the machine will do. What anyone else does is up to them.
And that is only for the PR system one machines that I asked about not Resmed etc.
Info for what its worth to anyone.