A quote from the man himself.
"I was flattered when Fender said they would make a Mark King Sig Deluxe Jazz bass. I spent some time with them designing the dead flat fingerboard profile. They sound fine, have Sims led`s in the neck and I love the transparent blue colour but they are so neck heavy and impractically weighted, you have to keep both hands on or the neck just heads south."
And Mark`s personal Jazz (he has 2 I believe), have gaffer tape on the pole pieces of the bridge pickup.
So, the man who helped design it doesn`t use them.