I am glad you built a successful low impedance pickup. I personally love the high fidelity sound they can reproduce.
Do you have a way to measure the inductance and winding capacitance of the pickup?
The only reason I am asking is that with a low impedance pickup it is possible to have a ultrasonic resonant peak which might cause issues with some, not all, microphone input preamps. With those numbers it would be easy to model the pickup and see if the resonance would be an issue, and find the optimum termination resistance for the pickup.
If your mic-level input impedance is 10K or less though, it shouldn't be much of a problem however.
If you have room on the coil and want to experiment further, you might try going lower on the wire gauge (#32 to #36 AWG) and be able to get some more windings without the DC resistance going up, for a bit more output.
Take care and enjoy the sound,