Re: I hadn't realised what Pocket was
"I wish there was an easier way to do a new-install configuration. Install these extensions, disable this that and the other, and change the UI in the following ways."
Install, configure then take a backup of the relevant identities directory and profiles.ini file. You'll find adding that to a subsequent new install (even on a different machine, or OS), everything will be as you set it without having to chance any config options. Bookmarks, history, passwords, installed extensions - it's all there. So adding that to a fresh install before launching FF will save a lot of config time.