dont forget to push this button before sending to Layout or exporting to DWG. Creating scenes creates your elevations and plans whilst organising layers and styles. You can dimension and annotate in Sketchup yet Layout is the best place to do it.
If you want to leverage the best out of Sketchup and PlusSpec you should take a little time to explore and use the exporting to Layout option then using Layout to produce your working drawings. It really is a seamless method and Layout offers complete flexibility in how you present your drawings. One of the big advantages is the fact that if you alter yoru Sketchup model those changes are reflected instantly in your working drawings, no need to re-export or re-import.