I've tried for hours to find information on how bad the thermal bridging is of their SIPs but can't find anything. They have a radiant air barrier as their outer sheathing and they use 2x studs in their panels as well. It seems to me that their panels would have just as much thermal bridging as stick building.

It's ok, I couldn't find anything either so if I can't find anything, that usually means nothing can be found. I was just hoping I was wrong this time. Oh well. I'll just use common sense and say that their panels have thermal bridging.