Hah, great dinner but actually almost the opposite fuel problem.
Part of my attempted roadside fixes for the gas overflow was to swap the fuel feed lines going into the tank switchover valve in case it had failed in the main tank position and was sending extra fuel into the already full aux tank through the return line.
When the did the aux tank, they spliced the fuel sender wires for both tanks into the switch so the gauge read the correct amount for whatever tank you were on.
Well, I didn't pull the switch to swap those wires around when I swapped the feeder lines so the gauge was reading from the other tank and I ran the aux tank dry because I hadn't though to flip the switch to check the aux tank level
Luckily, at the first stumble, I realized what I'd done and flipped back over to the main tank which still had a few gallons in it. Got to fix the switch (and the electric valve) or decide to just pull the switchover valve altogether. I'm thinking about just using a manual valve to replace it and make it all dead simple.
On this topic, I called Aerotank and they said that the filler tube does stop at the tank wall, it does not continue down into the tank, so the only possible reason gas was coming out of the filler was that it was running off the main tank and returning fuel to the full aux tank.