When I ask if the Oculus software is installed I meant the one on your Computer. I added the link to the install above. But if you have the values now in Regedit, you should be good.
MSFS is a beast but give it a try with Virtual Desktop and see what suits you.
There is no need to buy the official expensive cable in order to use the Link, I have this one and it works flawlessly (USB-A to USB-C):
https://www.amazon.com/gp/product/B087RB14HF/
Note: If you ever need to switch back OpenXR to the Oculus Runtime, the easiest way is to opt-out of Beta and opt-in again.
Or you can go back in Regedit and change the ActiveRuntime value to:
[Oculus installation folder]\Oculus\Support\oculus-runtime\oculus_openxr_64.json