Having spoken with Tim at length about hum cancelling single coils, I know he is very well versed in all the different types of construction, from the Kinman stacked ones, the Dimarzios based on the same principle, the various Duncan stacked and side by side versions, the Barden type, the early Gibson sideways type, designed by Walt Fuller and eventually used on some bass pickups, the Dan Armstrong adaptation of this design which was also used by Bill Lawrence in the 70's and Kent Armstrong later.
Tim is aware of all the details and could easily design his own version but so far he hasn't met his own high standards for tone in a humcancelling single coil design. I know he is extremely open minded about pickup design but the final goal is the tone.