With APFS, Time Machine underwent major change, to using snapshots to determine what to back up, rather than FSEvents. How well has this worked?
snapshot
Adds support for local snapshot statistics, Dark Mode, fixes a bug, and is now notarized for your added security.
Detailed comparison of how Time Machine backs up HFS+ and APFS volumes, including its use of local snapshots, with diagrams.
When Time Machine backs up an APFS volume, it works quite differently from the way it did on HFS+. Explored here using log entries from Mojave.
Does APFS support its major new features – clones, snapshots, etc – yet, and how can you use them?
One of the major ‘new’ features in the new file system coming in High Sierra. But how does it help the Mac user?
On laptops, Time Machine’s ‘local snapshots’ have been of limited use. In High Sierra, this all changes, and for laptop users should be a strong reason for upgrading.
The Eclectic Light Company 