But if you want to pick one: Inline replies.
Right now, I have to do a ton of magic to make that happen in order to work around your auth flow. Namely, pulling the auth token out of the other page and then having to keep track of it in session storage.
I could delete a whole lot of code if that was just built in.
The browser extension I wrote years ago, and which tomhow and I use for moderation, does this. I feel guilty about not having shared it a long time ago, but there just has never been time. Now that LLMs are starting to let me do things I've wanted to do for years, there's a chance I'll actually get to it before the sun dies.
And yes... AI enables so many things.
Please tell us you're not going to start vibe-coding HN.