Not an expert on secret sauce but thought the secret sauce was...

Not an expert on secret sauce but thought the secret sauce was part of BRN’s IP and architecture.
My understanding of the process is vague and I’m still learning but..
There is always that gap to be bridged between BRN’s architecture/Register Transfer Level (RTL) code and the implementation of that abstract being converted to actual circuits on a chip/ASIC by the engineers at Socionext.
This is not a straightforward process and is where the collaboration comes in between BRN and Socionext of course.
There was that video posted here by someone recently in which an engineer demonstrated that gap on a white board.
As for patentable parts of production process? Refer to JTard and BSitter perhaps...