I got my Frame today and found an unlabeled button at the side. Took me a bit to find out what it does. It's actually a mouse button! When you click it once the cursor appears and from then on works like a mouse. Only trouble is that the cursor is right in the middle of the screen and you control it by moving your head.
Guess it's good in a pinch, when you don't have the controllers. Could be more useful if it used the eye tracking. Maybe with a later update.
I played around a bit, installing basically every VR game I have to see if it runs. Unfortunately none of them (or SteamVR itself) support lying on your back while playing. I'm disabled and basically can't leave my bed. I was hoping for some setting to reset the pitch when you reset the forward view.
While it does position 2d windows wherever you look, that isn't the case for the VR space itself. The floor is always downwards and not in the direction my chin is pointing. I think OVR Advanced Settings can give me that option. I just have to wait for them to add Steam Frame support, which is supposed to come with the next major version.
Still I was pleasantly surprised to see that many VR games just worked out of the box. At least the initial screens worked in Droid Works, 7th Guest, Spellbound Spire and I Am Cat.
What outright refused to run was Batman, The Lab and Spider-Man: Far From Home.
I also dabbled with the Linux port of MotherVR, the VR mod for Alien Isolation. For a moment it actually worked. Only trouble was that a second window with the game scene was showing over the VR view. But just positioning it outside of view kind of fixed that. In my quest to fix it probably I must have broken something because now I can't get the game to work at all.
And on the topic of Quest, I grabbed Minecraft VR from SideQuest. I could not find a GUI option to add non-Steam games. But on the command line it ships with the script steamos-add-to-steam. You just have to modify it to also accept files with the type application/vnd.android.package-archive. After it was added I selected Lepton as the compatibility layer and to my surprise it started. Only running Minecraft itself did not work, as it complained about some missing libraries. Seems like a solvable problem.
All in all I've still got a lot to tinker with. Maybe I can whip up a quick SteamVR plugin to solve my laying down problem. We'll see.