Hi Stu,
Single “Layer” copy and paste only AFAIK. Copy the whole material, set up the other channels in this new material, if they are less complex, and use it as wanted.
You might check with MAXON itself, but I guess, as I haven’t seen in the past 18 years a way to copy several parts of the material (e.g., Fusion Shader or Projector) all at once, that you have to leave a suggestion only:
http://www.maxon.net/support/suggestions.html
I saw a while ago a node based material system, I’m not certain how well it did and if it is available for R16. http://www.cmstuff.com There might be an answer for such questions, ... maybe. But check out the suggestions or even the support.
All the best
Sassi