Continued on my previous post, without further complicating, I think that the solution can be even simpler for development. While at the same time users who want something closer to private messaging can be satisfied.
Option to group all private discussions under the Private Discussions tab.
It can be the same as All Discussions, but instead of showing all discussions from all tags, it will show only private discussions from all tags.
I would be more than happy to pay someone to "prioritize" work on this solution. Hope you will accept this and someone will get back to me 🙂