Vlad I can! As you can see in the video, only some extensions won't work. Note, the extensions were downloaded from Firefox, not Chrome, though I tried them from Chrome, and the same thing happened.
Also, when installing the extension “Canvas Blocker”, it 1) goes to a site, where one can press a button to go the settings, and this works… ? Last note: It says that the Firefox About:config setting “privacy.resistFingerprinting” turned on, so my question, is it really enabled, or just a bug with Canvas Blocker?