The main reason why you cannot perform an FLR from Storage Spaces Volume is that volumes from backup are mounted on backup server
thus if your Veeam Server is not of the same Windows version as the VM being restored then it won't recognize the Storage Spaces file system, just like with HDDs that used to be behind RAID controller. The Instant-Recovery workaround is the way to go, indeed, and it's documented in our KB
. Another way would be to have backup server with the same version of Windows as in VM and try to import Storage Spaces
there, which is not convenient because you cannot have a separate backup server for all versions of Storage Spaces.
So, I agree with you that some sort of check should have been implemented in order to warn user about the difficulties described. Your post has been considered as a feature request, hopefully this will be addressed in future release.
Thanks for heads up!