Is there a simple way to list the components in your design, sorted by a complexity metric like polygon count or data size? I would like to know which ones are having the worst impact on file size and Layout rendering performance. I figure a list like this would be a good place to start.
You could create a collection of the components and look in their directory to see which ones created large file sizes.
You can probably get a decent idea though by just eyeballing the components to look for dense geometry and large textures.
One thing I’ve found useful when working with SketchUp models in LayOut is to turn off layers for anything not visible in the scene.That helps to improve rendering times.