Isn't that creating hardlinks between source and dest? Hard links only work on the same drive. And I'm not sure how that gives you "time travel", as in, browsing snapshots or file states at the different times you ran rsync.
Edit: ah the hard link is between dest and the link-dest argument, makes more sense.
I wouldn't bundle fs and backup compression in the same bucket, because they have vastly different reqs. Backup compression doesn't need to be optimized for fast decompression.