So I replaced Cinnamon with Xfce. Easy. Lazy way: Installed Pamac so it was easy to keep track of everything. logged out and then back in again.
Took another snapshot in Timeshift… and right now it is still analyzing differences and claims the snapshot will take 15+ hours. My guess is that it goes through all the old snapshots and realizing Cinnamon is present and Xfce is not in all of them?