I used to do something similarly complex to the OP with ssh and --link-dest to make it share inodes so I could easily keep N days of backups with file level deduplication [1].

Then I moved to Borg and haven't looked back. It does the same end goal in a better way, is way faster, and easier to work with overall [2].

[1]: https://nuxx.net/blog/2009/12/06/time-machine-for-freebsd/ [2]: https://nuxx.net/blog/2019/11/10/using-borg-for-backing-up-n...