But I am not familiar enough with the firefox code to do this. I might unknowingly create a whole new set of security issues by changing a few lines in a project of this complexity.
Then you make a custom mozconfig file to disable or enable features, or to add your own extensions (ie: windows): https://developer.mozilla.org/en-US/docs/Mozilla/Developer_g...
ac_add_options --disable-activex
ac_add_options --disable-activex-scripting
ac_add_options --disable-installer
ac_add_options --disable-crashreporter
But I agree, I can't find any documentation what exactly every feature is and why you would not want to disable/enable them. The Chromium build process is much more straight forward, or you could just use 3rd party sandbox and regular release FF.
https://developer.mozilla.org/en-US/docs/Mozilla/Developer_g...
On Linux I clone the source and run "./mach build".
They aren't suggesting using compile flags requires code changes...