Initially I also wanted to implement things so that when a relative url is clicked to the settings that the state of the url is changed instead it reloading the page.

Almost wish there were a RES feature to revert Reddit's garbage link handling in all cases. I know it's a relatively new thing on old Reddit at least. There's a lot of on-the-fly href modification that happens in response to link clicks that ideally we'd be able to override, but I don't think it's worth it for us at this point.

Anyway... Before I dive into the code here, is there a reason fragments are being handled in a separate function from the existing URL change detection? My understanding is that the existing stuff should handle hash changes the same as any other part of the URL changing. Correct me if I'm wrong.

Anyway... Before I dive into the code here, is there a reason fragments are being handled in a separate function from the existing URL change detection?

Mostly because refreshUrlContext() already is fairly long and deals with actual page changes where this deals with hashes. So it made sense to me to separate the handling of the two to keep things readable.

I started out with all the logic within refreshUrlContext() but that was a bit messy, so I separated the hash specific stuff to refreshHashContext() and called that from within refreshUrlContext() and at that point I decided I might as well separate them entirely so they can also be worked on independently more easily if need be.