Oh thank you so much! Some of these exclusions make some sense to me but having my ctrl+n mashing interrupted by support.mozilla.com was fairly frustrating. Also security wise if I install a malicious extension with permissions to abuse these domains I'm already a goner haha
Mozilla believes that it creates a security risk and that you shouldn't do it.
[1]: https://www.ghacks.net/2017/10/27/how-to-enable-firefox-webe...