This is a Firefox user.js that tries to modify from this gist (or newer). This has recently been expanded to also modify with reference to Betterfox, in particular, user.js as in the repo, which is a combination of every other "distribution" in Betterfox.
git remote add upstream [email protected]:68e79da1c965aeaa4782914afd8f7fa2.git,
then perform the diff's as necessary, with
git difftool (-d) upstream/master:user.js user.js.
Currently detailed here. There is a corresponding Makefile command that translates the user.js into appropriate firefox.cfg.