3D Stager doesn't currently support its own native file format (.ssg) within the Assets > Libraries panel, yet supports more generic formats with less functionality. This is crazy!
.ssg files natively support all the features within Stager, specifically both Physical lighting (spot, area, point or directional) and materials. Other file formats that the Libraries panel does support (.glb, .obj, usdz, .gltf, .fbx) dont support both, so there is currently no way to create 3D models which support both materials and physical lights that can be saved in the libraries panel.
This is a major issue when a scene has been created and an additional model needs to be imported from the library, say a model of a street lamp or desk lamp with both physical lights set-up and surface material patterns built in to the .ssg file. Only way is to laboriously go through File > Import > 3D model - then find the file location. Would be so much more simple to drag and drop the preset from the library panel.
.ssg needs support in the Libraries panel ro suitable alternative option.