Hi All, I got OpenComposite working wonderfully and thought I'd quickly share how:
Machine specs:
CPU - AMD Ryzen 7 5800x3D
GPU - AMD Radeon 7900 XTX with driver 23.7.2
Headset: HP Reverb G2 using the controllers that came with the headset
If in the past you ever tried the vrperfkit and you still have the dxgi.dll file in the VAM directory, go ahead and rename it to something like dxgi_nonactive.dll to disable it.
Also, if at some point you've tried the fsr mod, go into VAM/VaM_Data/Plugins, find the openvr_api.dll and if it's the fsr mod version of the file, rename it to be openvr_api_openfsr.dll to disable it. Normally you would then re-enable the default VAM openvr_api.dll file, but in this case do not, keep reading below.
@miketruck69 mentioned in a prior reply about the skyrim mod version of openvr_api.dll. This particular version has a few extra parameters that it accepts, and important for Reverb G2 owners, are these:
leftDeadZoneSize = 0.2
rightDeadZoneSize = 0.2
Download the skyrim dll file and place it into VAM/VaM_Data/Plugins/openvr_api.dll.
Also, in the VAM folder, create a blank text document called opencomposite.ini and place the left/right "DeadZoneSize" lines in it as shown above.
Download the "OpenComposite Runtime Switcher (OpenXR)" app. When you launch it, click the button "Switch to OpenComposite".
Launch VAM by using the VaM_Updater.exe, and then clicking on the "Launch VR" button. For me on the G2 headset sitting in the windows Cliffhouse, for some reason my G2 controllers are unable to "click" the "Launch VR" button, so I do that with the mouse.
Instead of the black Steam VR load screen, you'll be greeted with the white/blue triangles of the Windows Mixed-Reality Open XR launcher. For some reason, it usually does this three or four times in a row... as far as I can tell, that is normal or necessary for some reason, but after a few times, you'll find yourself in VAM, with fully functional controllers including joystick navigation (although, see note below).
This is a MASSIVE boost in performance. Night and day difference! Totally worth the trouble! You can tweak things on the open composite menu (F2 on your keyboard).
A note on the controllers: Most of the time, they work perfectly. Now and then the game will launch and the little dots that represent the controllers on the menus will be visible, but the buttons won't work to select anything. I am not sure exactly why it does this, but the best observation I have is that it may have something to do with pressing a button on the controller while the game is still launching into VR. If you encounter this issue, just try to "Launch VR" from the VaM_Updater.exe a few more times in a row, and I am betting after about five times or so, you will eventually discover that your controllers work exactly how they should.
Another note is that most other instructions would tell you to either use the skyrim mod's DLL file, or, to use Open Composite's DLL file, but not both of them together like I have done above. And technically they might be correct, but for the Reverb G2 controllers, I believe combining the two like above is a good scenario in order to fix the controller drift by using the "dead zone" updates that were added to the skyrim mod as an intermediary before that DLL passes control along to the OpenComposite DLL (at least that's how I am imaging it works). It's probably worth noting that, as shown above, I did NOT do an application-specific install of OpenComposite. Rather, I did an application-specific install of the skyrim DLL file, and a global enabling of OpenComposite, which can be easily turned off if needed for other games later.
It should also be noted that in the above configuration, I am not seeing an option for fixed-foveated rendering on the F2 menu in the open composite settings. I see this in other games, but perhaps the skyrim DLL has somehow disabled this, I am not sure. It would be nice to have if that can be figured out, but controllers that work (and also don't drift!) is more important.
I hope this helps someone. Let me know your experience with this approach if you try it.