To easy understand what i am saying, i will give you this example, you visit domain.com but on this page there are other things from external domains other than domain.com that firefox fetches/connects to - cdn.blabla.com; third-party.socialwebsites.com, etc. What i want, is to simply not connect to any other domain except what i typed in url bar. I understand it can break pages but i dont care.
A while ago, setting permission.default.images to 2 somehow worked and stopped loading of external content. Disabling prefetch/preconnect/predict/predictor does nothing.
p.s. i dont want to use extensions, only about config.
That setting was probably only blocking external images and not scripts or fonts in the first place. Why can’t you just use ublock?