Yes I managed to get OVR Toolkit running in MSFS 2020 VR:
- Start Steam
- Start Steam VR
- Start OVR Toolkit
- Start MSFS 2020 (I have the Microsoft Store Version)
- Switch to VR in MSFS 2020
- Take your left controller and turn as if you want to read your wrist watch
- Menu shows up with which you can controll the windows
- Connect the window you want to see in MSFS to your right controller
- Trick: With Alt Tab you switch from your Window to MSFS and can controll both with your mouse
It´s just a rough explanation
Happy landings