Single coil pickups can be tapped as many times as you want. You can tap a pickup at desired number of turns or at pre-determined DC resistance. Tapping a pickup at a desired DC resistance takes more time and measuring the resistance at various readings. We have a way of measuring the DC resistance quite easily while the coil is being wound on the machine. Remember that the DC resistance can change when using the same gauge of magnet wire with different insulation’s. The thicker the insulation will generally have a higher DC resistance than the exact same magnet wire with a thin insulation. As the coil is wound the diameter influences the number of turns per layer and total number of layers.

I’ve tapped pickups with as many as 10 taps on a custom Telecaster order using a 10 position rotary switch in place of the tone control, and I replaced the volume control with a Jazz Bass stack knob volume and tone control. As the DC resistance went higher, it also increased output and fullness.