This is a known quadratic behaviour with a testcase. Worth biting the bullet and just fixing it now?
Bug 1968172 Comment 2 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
Still repros: https://share.firefox.dev/4oEqOFn This is a known quadratic behaviour with a testcase. Worth biting the bullet and just fixing it now?