Not a big fan of the file folder look of it, but I’d guess that tab portion will probably be used for notifications/clock/status icons.

I suspect it only reports the activity from that instance. Definitely feels like there is some room for improvement.

Check out Jerboa for lemmy. It hits a lot of the features the I loved about Boost. The app is fairly early alpha but if it keeps going for a while it could be a drop in replacement.