I don't know who @J Wilson was talking about, but Yamaha consulted with a lot of West Coast studio players on those early BB series instruments. Abe Laboriel was another that was known for playing BBs and has since been a loyal Yamaha player, but has never had any kind of production signature instrument. I always found it a little odd, given his loyalty.
Nathan East had a lot of input on the voicing of the BB pickups.
He talks a bit about it here: