SOLUTION/FIX
I can not believe that I actually found the problem. I just did 30 minutes of flying over Vienna (LOWW addon airport aswell) without a single freeze. Also no freezes in pancake mode. It is not a GPU related issue, nor RAM. It is a Reverb G2 USB power/connectivity issue.
How to check if you have the same error:
Go to your “devices manager/geräte manager” → Observe if the list refreshes multiple times in random timegaps
If it does open the dropdown menu “audio, video and gamecontroller” inside the device manager.
In there you should see an entry called “Realtek USB2.0 Audio” (you see it when your Reverb G2 is connected). If not wait until the next refresh it should pop up again.
If this happens you have the same issue as I had.
This is the “audio” of the Reverb G2. I always had the suspicion it could be sth. USB related as it is a known cause for FS2020 freezes, but never had that parameter in sight as I focused on the connected USB device list.
I then discovered that at every refresh the “Realtek USB2.0 Audio” disconnected and then reconnected. (visible and not visible in the list)
ONLY when I then decided to plug the G2 into my externally powered USB3.0 Hub (which I bought some time age as the G1 ran better with that aswell) the connection was stable and ALL refreshing inside the device manager stopped. This is the fix.
So in short - If you have the same connecting/disconnecting and refreshing in the device manager as I had make sure to CONNECT THE Reverb G2 to a externally powered USB 3.0 hub or try to find a usb 3.0 port on your mainboard that gives a 100% stable connection that stops the device manager refreshing.
I hope this solution is clear to understand.
@markymarksti @Ramasurinen @gosub4000 @KennyKanada @OSalvadorO