First observation, probably a typo, but the type is REG_MULTI_SZ not REG_SZ_MULTI as reported.
Can you confirm you're actually using:
A screenshot of Regedit would have stopped me nit-picking those details.
Assuming that key behaves the same as:
Then both Registry keys for backup and restore
and Excluding files from shadow copies
from Microsoft are interesting reads,
The latter contains the following please note the final bullet point:
The FilesNotToSnapshot registry key is intended to be used only by applications. Users who attempt to use it will encounter limitations such as the following:
- It cannot delete files from a shadow copy that was created on a Windows Server by using the Previous Versions feature.
- It cannot delete files from shadow copies for shared folders.
- It can delete files from a shadow copy that was created by using the DiskShadow utility, but it cannot delete files from a shadow copy that was created by using the Vssadmin utility.
- Files are deleted from a shadow copy on a best-effort basis. This means that they are not guaranteed to be deleted.
Also the first linked page has this, I've added some bold:
Applications that perform volume-level backups generally do so by copying the entire volume at the block level, so they cannot honor the FilesNotToBackup registry key at backup time. Instead, they wait until restore time to delete the files that were not to be backed up. In most cases, this is a reasonable strategy. However, in the case of Single Instance Storage files, the SIS Common Store files must not be deleted at restore time.
If that's what Macrium is doing, which seems reasonable, @jphughan
might know for certain, or someone actually from Macrium. Then only a test restore will tell you if they're excluded, not simply browsing the image.
If you don't want them there at all, then I'd suggest modifying the process for backing up non VSS aware databases here
& using the batch files to temporarily dismount those virtual filesystems during snapshot creation, assuming Cryptomator has a command-line interface for mounting & unmounting them.