If you export your CAM settings, they can be imported into the next design.
One handy feature is that the files is ASCII text. If you have a different number of routing/plane layers, you may find it easier to man-read/decode the CAM settings files and add/delete layers there, then import back into your PADS design file.
You'll find that you need to change the layer number and name in 2 or 3 locations in each layer section to match your Layer Definition settings.
This really only affects your routing/plane layers since your documentation layers (probably) don't change.
Hint: You can do the same ASCII man-read/edit on the *.pdc file that controls the "Create PDF" output!