Which browser extension is responsible for making Firefox slow as a slug when deleting large numbers history entries?

I've not checked the source, but my guess is firefox stores the history in a SQLite db and when you select 500 history items then delete them, it's doing 500 DELETEs, maybe even without a proper index. It's seriously slow.

There seems to be a lot of low hanging fruit in Firefox, but not being employed by Mozilla I don't particularly feel like my thoughts or contributions are welcome. The last time reported a bug on bugzilla.mozilla.org (which is a pain in the neck) I was told that accessibility on MacOS wasn't important enough for Mozilla to care about (paraphrasing.)