For Bazzite , I search for “how to do X in Silverblue”, or “how to do X in KDE”

Bazzite is built on the same technologies as Fedora Silverblue (immutable base, ostree, btrfs etc).

You probably already know this, but just to be clear; Timeshift (by default) only backs up your system, but not your data, documents photos etc . Basically everything outside your Home directory.

You can probably tell Timeshift to also backup your home directory, or install a separate backup app for that.