The Roland hex pickups can be adjusted in width to cater for different string spacings (albeit a little crudely as it's just varying the gap between the two halves) and can accommodate 4, 5, or 6 strings. I have two, both on 6 string basses.
Sei Flamboyant with built-in kit:
Sei pickup and controls (toggle switch does pickups/Roland/both, puchbuttons do patch up/down)
Handmade (not by my hand) 6-string with GK3B externally mounted