I don't know what response to username feature requests you're talking about, but AFAIK they've been saying for a long time already that they're working on that

I don't know what response to username feature requests you're talking about, but AFAIK they've been saying for a long time already that they're working on that ­— but it's a significant rework of their architecture, so it understandably is taking a long time, especially to also do so in a privacy preserving way.