[BluesJam]

Has anyone tried to use the bottom coil of a bridge position HS2 to create hum cancelling  of  fender single coils in the middle and neck positions?

[mmmguitar]

It can be done, though not as easily as mounting a dummy coil in the control cavity. In either case, all three pickups need to be the same wind and polarity to share one hum-cancelling coil.