Put any preferred tweaks in a user.js file in the profile directory, // commented with meanings and reasons,
and save wetware memory.
Now I am older and tired of doing the symlinking every time I setup a new install of Ff.
I've been moving around the same firefox install since Opera died.
https://bugzilla.mozilla.org/show_bug.cgi?id=1543752
It's a slow and steady advance, not something that happens overnight.