Note that I have a patch ready for this (my moz-phab is busted though, need to fix it so I can push my patch to Phab)
Bug 1967707 Comment 3 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
Note that I have a patch ready for this (my moz-phab is busted though, need to fix it so I can push my patch to Phab) To have an invalid cookie, you can add one from the storage panel, and then edit its name, adding a space before it