Similar to Azure Spatial Anchors, partners were struggling to leverage the Unity samples for Scene Understanding and Jared helped organize the code into reusable SDK. He also greatly improved the visuals, added an ability for each SU object kind to have its own Unity layer for physics purposes, improved rendering performance and improved asynchronous execution. These changes are part of the official repo. (Source)
Microsoft Mesh
Though details about the role and platform remain confidential, MRTK and large-scale multi-user interactivity were key focus areas.