I didn’t know about the “test version” that came and went. The current USN implementation start:
Implemented backup based on changes recorded in NTFS USN journal #3184
v2.0.3.7-2.0.3.7_canary_2018-06-17
Added support for using the USN numbers for faster backups on NTFS drives, thanks @dgehri
v2.0.4.5-2.0.4.5_beta_2018-11-28
USN support on Windows
and doesn’t seem to have any clear open issues besides:
With --usn-policy=On, source deselection retains files and folders from removed items #4071
which (as failure to remove files when config tries to remove them) is probably more tolerable.
Full scan may also occur even with USN because journal has a finite size and might overflow.
So I have some hopes that USN could help : )
Certainly seems worth a try. Despite lack of issues, feel free to watch carefully and report any.