I don't advise turning this on because I think automatic updates in most cases are preferred to manual updates for most users. However, in Firefox you can in fa

I don't advise turning this on because I think automatic updates in most cases are preferred to manual updates for most users. However, in Firefox you can in fact disable automatic updates on a per-addon basis. So you can have the addons that you trust automatically update, but for the addons that you're less sure about or that basically already work, you can just turn off updates for them. Just go to about:addons, click on the addon you want to change, and then swap "Allow automatic updates" to off. You can also change the default behavior to not automatically update except for individual addons that you override (although again, I don't recommend it for most users). I don't believe you'll get notified about updates (correct me if I'm wrong), which isn't ideal, so you'll have to periodically go and check for updates yourself.