I have one more thing I forgot to add actually: refresh rate of new replies in the inbox as well as how it is displayed. Sync seems to be quite slow when it comes to refreshing inbox. I've been jumping between apps a lot today comparing stuff like markdown support, and often I get an alert on another app, but have to manually refresh the Sync inbox to see I have replies.
I'd also like a ! indicator somewhere in the UI for new replies in your inbox that is visible no matter where you are currently (such as to the left of the Search 🔍 icon in the top bar).