I use this for Opera, FF, and Edge. For some reason, this extension causes RAM chewing issue only with FF. This is an only extension I use for all browsers I have and FF begins to chew RAM up to 1GB/hr or 2GB/3hrs in idle. The problem does not occur with Edge and Opera (or any other Chromium based browsers). I am not sure if it's caused by codes of FF or of this extension but the problem exists with all of FF, FF Dev, and FF Quantum. Besides that, this is "the solution" I found for blocking popups.