A user may wish to exclude certain addons from update consideration, but would like to use the "Update All" operation for all other addons.

I propose an "Ignore" button inside the "Details" view of each addon. Clicking it will add the Addon to a list of ignored addons and remove it from the list. The addon will stay ignored through refreshing the list or restarting the application.

Ignored addons can be "unignored" via the Settings view, (or alternatively by editing the config file they've been added to).