... In the end the neck is the most crucial part and the backbone of a stringed instrument.
In fact our through-body neck is almost our entire instrument. The body is just glued on to the sides.
Yes the graphite necks Alembic began experimenting with in the late '70s were built as a long, mostly hollow beam which extended into the body. I think were deemed so stable that they did not require a truss rod. But as others have commented, that meant any bow or relief the customer wanted had to be built-in. It also got complicated if for instance an ebony fingerboard was used because ebony can expand and contract with tremendous force introducing a bit of instability.
There was talk about adding graphite laminates to the neck "sandwich" when I was having a couple basses made in the late '80s I had actually requested that on one instrument but I don't think the made it into the final build. And I'm pretty sure it was never offered as an official option.
About the dual truss rod setup - and I'm only guessing here - I presume the reasoning behind that relates to our long two-octave necks which extend so far away from the body. It's a longer span than most, particularly on long- and longer-than-long-scale basses. It makes sense that two rods would offer more control and fine adjustment capabilities
I think Stanley plays mostly short scale basses, so...
Jimmy J