JIRA web eats all my memory on Firefox, so laggy that pressing a button takes 3 or 5 seconds, not to mention page transitions. It only becomes usable when I add the uBlock Origin rule[1]:

  yourcomany.atlassian.net##+js(aeld, /^(?:mousemove|pointermove|pointerout|pointerover|touchmove)$/)

[1] https://community.atlassian.com/forums/Jira-questions/Re-Re-...