If I understand correctly, they are implemented by adb commands that set the resolution. For example, for resolution 3072, the command would be:
adb shell setprop debug.oculus.textureHeight 3380
adb shell setprop debug.oculus.textureWidth 3072
To set the frequency, use the command:
adb shell setprop debug.oculus.refreshRate 90
It is not possible to set the resolution for a specific game, it is always set globally. In QGO and QGT different profiles are used for each game. These profiles have their own settings for resolution, frequency, FFR, etc.