I noticed that it doesn’t show a game on the Configure page until I run it once. If the OpenXR splash screen is showing when DCS starts in place of the SteamVR one, then you are good to go. But if it isn’t, try renaming the D3DCompiler_47.dll in the bin folder.
Mine looks like this now. I had to run these games once before they showed up.
“These games use an old version of D3DCompiler_47.dll that is incompatible with some OpenXR Runtimes. If you experience an error with OpenComposite resulting in a -2 error code then find the D3DCompiler_47.dll in the game install dir and rename to D3DCompiler_47.dll_orig. This will then use the one from your system path that should be the latest version if your system is up to date.”