Hey John.

I have tested it on several sites. If there is one that does not work, please mention it specifically. I will work to figure out why and make it work.

Unfortunately all firefox content-script addons are disabled on the addons.mozilla.org site (as a security measure so that one addon cannot maliciously install further addons I believe).

(the note right above this link is the only stated documenation I could find). https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Modify_a_web_page#Modifying_pages_that_match_a_URL_pattern

Sorry for the confusion on that. Hope the addon has been useful otherwise. And I will endeavor to test it on more sites as I come across them.

I appreciate the feedback, sorry for it not working in that particular case.