Walls - Am I missing Something?

Thanks guys, as I mentioned we can do it and I agree with the new layer to enable us to control plan views for dimensioning reason. There is a fine line between how much detail and and how little detail to put in. If you are looking to do detailed sections in the short term I suggest mining into the wall lining and CTRL push pull to your desired thickness. I just did it now it took me about 5 seconds, I can make a video if that helps?
I personally am torn by the situation. The main reason PlusSpec works so efficiently is due to optimisation of geometry which essentially makes Sketchup work faster. If your main reason for wanting plasterboard thickness is cross section details then I would be more inclined to leave it the way that it is. It is possible to go right down to the thickness of lining plus thickness of setting compound and every nut bolt and screw yet the negative repercussions on a larger scale greatly out weigh the visual benefit. A good example of the negative effect is a 1400 room hotel I just designed. The total model size was under 7 meg yet the edge and face count was large, giving rudimentary products like internal lining would have render the model unusable on any computer with less than 4 gig of RAM and an I5 processor.
My main aim with PlusSpec is to reduce the cost to the end user and that includes the hardware cost associated with buying a computer. In saying that this is a democracy and if I get enough people asking I may revisit.
Thanks for asking guys & ill keep it in mind yet at the moment I have to go with the general consensus.
I am not sure if this helps with the cladding I use it when looking to do rendering it works fantastically.
http://www.rubysketch.com/brands/weathertex or use the cube icon on your PlusSpec tool bar andHow to download from RubySketch.png
Sketchup RubySketch Dynamic external lining.png