Yes, with welding and fabbing, it seems to mostly be an issue about where the welders pay their taxes.
The carbon frame geometry is proto'd in aluminium and then some magic happens with 3D solid modeling and FEA software and then a CNC 5 axis mill somewhere on the planet spits out a mold, then a bunch of unemployed frame welders smoosh carbon fibre into the mold and stick it in an oven heated by unused welding torches, and then a frame pops out.
But more to the point, the new frame designs aren't just picked out of a catalog, or sketched up and sent to production, they do lots of proto frames to tweak and adjust geometry and tubing, adjusting stiffness, let the test riders go out and abuse them to see if they can break them or make them wiggle and wobble riding on trails around Vancouver like the one below. If you see a rider on a raw aluminium frame on North Shore trails, there's a good chance it is a proto Rocky (unless it might be a proto Knolly).
When they get carbon test shot frames in to check over, they do the same thing with lots of test riding (which is how I was able to test ride a carbon Vertex test shot in 2008 back when one of the guys at my LBS had one to abuse in secret and I was able to spend a weekend with it

shhhh, don't tell anyone :nono: ).