Okay I just tried 6.2.0... it works on the 2d mirror, it does not work in the headset? My test was install as above, set to Monochrome (because its simple to tell), exit DCS and then restart and put on the headset ... and in full living colour ... so my assumption was maybe its a ordering API layer issue in Open XR, tried it first and second and last no difference, still full living colour?
are you by any chance using SteamVR for OpenXR ?