I don't see anyone mentioning the ability to store about:config settings in a user.js file.

Unless you have some reason not to use it, it's much easier than changing about:config on each computer, you just copy over the user.js file.

Here's a hardened option (no affiliation): https://github.com/pyllyukko/user.js

And a relaxed version: https://github.com/pyllyukko/user.js/tree/relaxed