I would think a radiator on the outside of the case would also affect results from those compared to ones that were on the inside. I understand you need to compare like for like (Intel kinda proved that, too). But to me, that means putting all units into a proper case that fits. Yes, that would mean much more testing, but as you pointed out, people that buy this are probably going to pair it with a case that can fit it properly.
I don't know, just saying. Just my opinion. Black Friday is coming, and I'm wish listing a new system, including case and water cooling.