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Results from the Browser Features Survey
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A place to discuss the news and latest developments on the open-source browser Firefox
Just noting: If one develops a firefox extension one can already restrict it via URL. That should be the first application one develops within the official tutorials.
You could even change this as a non-programmer as long as sources of the software are available.
At the expense of having to either hope devs do it or only use extensions that give the source, having to do it for every extension individually, having to redo it every time you want to add or remove a URL, no longer getting automatic updates, and having to redo it every time you want to update.
I get the sentiment but it's not worth the hassle, especially when it would be trivial to have this as a browser feature that would solve all of those problems.