A workflow that has been common for me form the early Sketchup 8 days was to bring in PDF plans and sections, scale and snip them in the model, then arrange them with each other correctly in 3D space. This is then my 3D background to which I build a simplified model for export to acoustic analysis software.
Up until SU 2015, I would import the PDF, scale the drawing using the tape measure, and then explode the PDF image in order to trim away the areas I don’t need or to split the drawing into separate parts.
Now in SU 2016, exploding the image leaves me with a blue plane that appears to have the appropriate image mapped onto it, according to Entity Info, but shows nothing useful on the screen.
The attached image shows a screen from SU2016 - on the left is the PDF imported, on the right is a copy of this but exploded.