Whenever I import a sketchup model as a Collada (.dae) file, it works fine but the object is not a single entity. Instead, it is a single parent object containing most of the mesh, but the rest of the mesh is split into many child objects. While this isn’t a significant problem, I want to know what causes this, and if the large amount of child objects could potentially cause lag.
Because of how Sketchup works, it renders each shape as an individual object. There is no way around this, but if you import to Blender and join all of the child objects, it will export as a .dae as a single object. Remember to unwrap UVs before exporting.