To answer the questions, yes the first cams are for the 991 GT3 engine programs. This same production type will follow into the 911 as well.
The 911 4 cam heads under development will use this same production and we have decided to do this for the standard 911 as well. The 4 cam shafts are smaller and use caps.
It becomes economy of scale. We can have lobes cut in numbers and these can be used in any camshaft design, type understood. This means we can have all of the parts in hand, then assemble the cams like in "leggo style". The 9A1 cams have trigger wheels, pump drives etc that all can be made and then assembled onto what is typically a common shaft.
The 911 cams will be the same and even easier. Just lobes and journals and a common shaft.
We went without billet shafts for some time for the 911 cams and they are becoming harder to make and more expensive. Turkey is the only source for the world now. We will drop out of this and be able to make our own in any size etc.