I never set up the headset (as I was already using steam with the Quest), I tried running the viveport setup with the headset as a Rift, then hit skip when it wanted to reinstall steam. After that I got the Vive button in Steam Home and was able to go to Viveport. It seemed there it recognised that I had a 'rift' (Showed the correct controllers and suggested Rift games). I still get a warning message in the desktop app when I download Rift compatible games, that 'this game is not compatible with your HMD'
I haven't tried my games yet. Not sure if I will need to reinstall them. Hopef