this is the best read ever here. only other one that comes close is the "pictures of your mining rigs" thread. Kudos!

wonder how easy it would be to just whip another simple board up with the power and freq generator and wire it to a stick (or possibly multiple sticks).

ie, something external to the stick (with its own power supply and signal generator), with leads that you just solder to the stick(s). just need to cut some traces on the stick(s), solder some leads, pull some parts and off you go. something you could do fairly easily to a stock stick with no mad scientist skills needed. Im thinking 555 timer , LM317/mosfet skill level. (not those exact chips maybe but you get the idea)

course, need some cooling mods but thats easy compared to the work youve done.