I am sorry to say, but I think the whole “selective traffic VPN-only” feature is too geeky and benefits too few users to invest time and effort into it.
As per recent blog post:
upcoming usability improvements that will hurt, TLS downloads, abolishing torrent downloads
Sorry to come up with this so late, but this thread partially contributed to me finally recognizing that while trying to suit everyone, I am loosing focus on the main stream work.