Currently, as noted in the documentation here, when you import multiple meshes in a single file, only the first mesh’s custom collision will be imported. Are there plans to improve this? The ability to import hundreds or thousands of meshes in one document is wildly useful for modular sets (so that you can reimport and manage everything with one document as changes are made) but it is crippled by the inability to import multiple custom collisions at the same time.
Forgive me for not knowing where to find whether or not this is in the roadmap.