What's the deal with controller support?

That’s great for those who can use SteaVR OpenXR! Unfortunately I’m on Reverb G2 that’s only good for WMR OpenXR and thus it won’t work… Too bad, it looks great.

Actually from their website it seems the API can work in WMR OpenXR “for the applications that support it”, so I think the drivers that drive controllers based on UltraLeap still would only run in SteamVR… But it would be great if it would be a way to run UltraLEap in WMR OXR! Does anybody have that so they can test it with G2 in WMR OXR?