Decided to try for the beta as well, now that I have holiday to babysit the process.
2 drives started doing the upgrade (Drive is upgrading), 2 are stuck in "Drive initializing" and the 5 others seemed to work fine.
Due to Windows updates, I restarted the server after checking this thread and after seeing some weird issues (the mounted ones started saying it can't find the file when looking in performance settings, I forgot the phrasing of it) and found a bit of a grizzly sight.
The 5 drives that were "fine" are now unable to be mounted and my cache drive is completely filled to the brim (44k free). This could be due to some automation filling the earlier mounted drives, but I have never seen it be filled below the 5 GB limit. Now, they most likely cannot be mounted, hopefully, due to no space left on the cache and thus not possible to write to it, but as I don't have a functioning drive or any means to actually empty the cache drive, I'm stuck in a bit of a place where I am unsure if everything is lost or I just have to be patient.
Log says: [CloudDrives] Cannot mount cloud part xyz. It was force unmounted.
I'll try for patience for now.
So, be careful, out there.