I'm using SystemBack - forked and newly maintained now after a short period of abandonment - in place of Timeshift. Have a look at the new and improved SystemBack here (https://github.com/BluewhaleRobot/systemback).
I've been keeping an eye on it for years.
One thing it does and it works, and it's very useful: System Live Image.
I've done it, tested it and works! :D
For the rest, it's too soon to say something. It's too risky to work on my current machine. Anyway, here is an intermediate test result:
(https://i.imgur.com/Ai8UuIj.png)
I guess it's easy to figure out how much space it requires: over 60 GB. At this rate, I'd rather skip this feature.
Even if (supposedly) it uses incremental backup, still it eats way too much space.
I stick with CloneZilla and LuckyBackup (rsync).
Best regards! :)