I’ve been using the HP Reverb G2 in a 4.26.2 project with OpenXR, not completely without issues. I went back to 4.25.4 to see if I could figure something out but it seems to rely on the HP Motion Controller plugin which is not available to 4.25.4.
I read in an earlier post that one of the things you were having issues with was the thumbsticks. According to their documentation, while using SteamVR “…the name of the axis event must end in “_X” or “_Y” corresponding to the key used.” Without that pair SteamVR doesn’t seem to handle the thumbstick mappings.
Sorry to hear of your issues with upgrading your project. However if you do manage to upgrade, or if there is anyone else listening in and can’t quite figure it out then I may be able to help out a bit. I tested this out in 4.26.2 using a fresh Virtual Reality template project, so hopefully there will be no issues.
I followed the documentation that Tomas_TDFM linked earlier, but for the “All platforms” tab rather than SteamVR. You’ll need to enable the HP Motion Controller plugin, and make sure OpenXR is still enabled, then use the Oculus Touch mappings for your various inputs.
If you setup 4.26 to use SteamVR by default as mentioned previously in this thread, you’ll need to go back and remove vr.SteamVR.EnableVRInput=1 from ConsoleVariables.ini and set SteamVR=10 in BaseEngine.ini to ensure OpenXR is taking priority again.
The only mapping not available while using this method is the menu button on the right controller.