There’s certainly room for improvement! The decisions aren’t always easy. For example, long presses are good for some people, bad for others. I’m quadriparetic, so anything requiring touch is problematic, let alone different kinds of touches. For me, the most important thing is that the app be voice and switch friendly. Things like putting primary navigation at the top of the screen so I don’t have to step through every other option on the screen first make a big difference in accessible usability while other people might not even notice.
There’s a sneak peek of the new UI currently in development, have you had a chance to look at it?
edited to add: crossposted, same link.