How to back-up Blender config files

The corret way of using Blender back-up and exporting your user prefs should be done from the ~/.config/blender folder.

Navigate to ~/.config/blender/4.0/

Warning

Note that the 4.0 is the version number. So it may vary according to the Blender version that you are using.

In this folder you will see two folders at least: /config and /scripts.
You only want to export/copy the /config folder as it includes your userpref.blend file which includes:
- Your theme set-up.
- Your shortcuts.
- I am not sure but I suppose your startup file.
- Your quick menu set-up.

You don't need to copy or export anything else. In the other computer or your new Linux installation, it is enough that you copy these files, in the ~/.config folder, with the same folder hierarchy.

Importing user prefs to a newer version of Blender

If you have installed a newer version of Blender, you can change the version number in the folder hierarchy that you will be creating in your ~/.config folder.

Unless there has been huge changes between the version changes, it should work without problems. I did it between v3.6 and v4.0 and I had no issues.