Just been back and tried that startup without touching the Oculus desktop app and it’s been fine, VR enabled in the sim. I guess somewhere along the line it was on when I got it to work so just kept it in the list. So as you correctly suggest, not needed. 
It could be that you can start Steam VR earlier, I had a few problems getting it all to work initially once I switched to VD so kind of stuck with what works and left it alone to be honest.
Fingers X you get yours sorted