>Being able to change stylesheets https://addons.mozilla.org/en-US/firefox/addon/styl-us/ https://addons.mozilla.org/en-US/firefox/addon/styl-us/ >disable or

>Being able to change stylesheets https://addons.mozilla.org/en-US/firefox/addon/styl-us/ https://addons.mozilla.org/en-US/firefox/addon/styl-us/ >disable or enhance various JavaScript scripts https://addons.mozilla.org/en-US/firefox/addon/ublock-origin/?utm_source=addons.mozilla.org&utm_medium=referral&utm_content=search https://addons.mozilla.org/en-US/firefox/addon/ublock-origin... https://addons.mozilla.org/en-US/firefox/addon/tampermonkey/?utm_source=addons.mozilla.org&utm_medium=referral&utm_content=search https://addons.mozilla.org/en-US/firefox/addon/tampermonkey/... Yeah you can't directly alter scripts being ran (as far as I know?) but you can usually override/extend behavior and can definitely add your own >add notes and annotations https://cwmonkey.github.io/greasemonkey/make-note/ https://cwmonkey.github.io/greasemonkey/make-note/ (I haven't actually used this one, just first result)