We did. We got 4 4 ohm 50 watt resistors and an ON-OFF-ON switch to do 4/8/16. Worked like a charm.
Like Scottie said, we are a little embarrassed by not catching that cap grounding before posting to the board. If we had built the effects loop ourselves, I think we would have caught it.
Once again thanks for all of your help. This board has proven invaluable to us as we keep building amps.