Good work Sep! I think that you have found another way to restrict the current/voltage in the trigger coil allowing for a faster on off time. I would be interested to see if it affects your charging rate positively. Interesting too that your potentiometer can only do so much before it goes into solid state or starts drawing more. This is similar to experimenting with a pick up coil as your trigger. Maybe start adding more relays??? Aaron my understanding is similar to yours. Current cannot flow through until the magnetic field has built up. This choking coil may be restricting current just long enough to reduce amp draw.

Well done