kb,
I could not find your projects page, if you want I will post a topic here for you to share your progress. (or maybe I just overlooked it on this form?)
Basically what you are doing is increasing the current density to a smaller area. My cell has an open top at present - so I have no way to verify gas production except by amp draw alone, Faraday.
How are you measuring yours to verify 4x production?
Right now I am trying to figure out how to produce more current draw at lower voltages. I am thinking 2 areas here:
1, larger cell size - going super sized on the electrodes should allow more ions between the electrodes.
2, moving to a plate cell and making the gap smaller.
The farther outlook plan is attempt dissimilar metals on the cell.
My overall goal is achieve the low resistance (0.1 ohm or lower) without the need for the higher voltage. I think the SS has a lot to do with this.
Secondly overall goal is try again with the resonating tank circuit, maybe build a better driver that doesn't walk the frequency, but the auto tune is designed for maximum efficiency.