I do something similar but my live USB is just bootable Clonezilla. I’d like to hear more about why you use a live Ubuntu ssd.

Regarding Timeshift on btrfs, is the idea that Timeshift makes it easier to backup to a different disk versus using Snapper?

I’m also on btrfs and miss the wonders of Macrium Reflect. For now, in addition to Snapper, I’ve been using Clonezilla to make a disk image on occassion. I’m in the process of figuring out something like Vorta to replace that process.

Give me an open source solution that can import notebooks from OneNote and I’m sold!