@djh Scale doesn't make any sense for Perspective views. That's why it is only available for Parallel Projection.
Create scenes that show the model the way you want to see it in LayOut. When you insert the SketchUp file into LayOut, the boundary of the first viewport is determined by the size of the paper. It's unlikely that the aspect ratio of your paper matches the aspect ratio of the SketchUp model window. If the paper is oriented in Landscape mode, the height of the viewport will be set as a percentage of the height of the paper. The width of the viewport will probably get cropped a bit. That depends on the aspect ratios. If you only want a single viewport on a page, set up the scene so the model is well within the resulting viewport. You can use the Advanced Camera tools to show the safe area in the SketchUp model window. Figure out the aspect ratio of the paper you are using and either select a camera with the same ratio or create a custom camera to do that.