Hi everyone!
Hope you're all doing well!
At Synergiz (French Microsoft MRPP company) we've been creating HoloLens content since the release of the first hardware version.
We experimented a lot of tools to create HoloLens applications and we're now happy to say that we know what's painful and what's not in this process.
Therefore, after the deprecation of Unity Network, we decided to create our own multi-user (offline and online) solution.
Today, we're proud to release "LightHouse", a solution specifically designed to be integrated into Mixed Reality applications, allowing smooth and real-time multi-users interactions. 
We would be delighted if you could take a look, and we warmly invite you to try it for yourself : http://lighthouse.synergiz.com/
We would love to have your feedback !
Take care 
Quentin Louet