CptLucky8 is the authority here but this is how I’m running my G2. I don’t have SteamXR or anything to do with Steam installed on my system.
I have only MSFS (of course), the Windows Mixed Reality portal, which drives the G2 and is installed as part of the headset setup process, and OpenXR Dev Tools from the Microsoft Store here
OpenXR Dev tools allows tweaking of the settings, I’m using a 50% custom render scale and motion reprojection turned off. Once the settings have been tuned in OpenXR the application can be closed. The Windows Mixed Realty portal will always run when you’re in VR mode.