Messaging doesn't work

You need to click on it, so the name is added. It's a search field where you type the name to find the user, and then you need to select it.

So it works, although UI UX may need some work to be more intuitive maybe.

On further testing, there's a (I think Firefox-specific) issue that got me confused. The search field is getting interpreted as some kind of login field, so when you're typing in it, a "Manage Passwords" prompt pops up right in front of the dropdown (completely covering it if there's only one option, like if you enter a user's exact name). And most of the ways to make that prompt disappear also make the dropdown disappear, so it's really hard to figure out the dropdown is even there.

Oh, thanks for further testing. I'll look into it, if there's anything I can do about it. I guess there should be some kind of marker on the field to let password managers know not to trigger on it.

Ok yes, it was missing the autocomplete=off indeed. I'll mark it as fixed, and it will be when I push the next update.