I have an almost identical configuration to the OP (GTX 1080, monitor in DVI port, Vive in HDMI port, etc) except that I do keep steam running and VorpX works far better than I had expected.
OP you should click “Start VorpX” and then in your system tray make sure your watcher is enabled. Then start a supported game. Personally I suggest a Direct VR supported game like Fallout New Vegas since it’s the easiest to test and configure. Start a Direct VR scan once you enter the game level and NOT during the menu or anything like that.
As soon as you start the game, VorpX should show you an overlay in your VR headset as well as the game itself.