The real way to avoid the protest is to have the wheel itself contain the drillings that are in the spacer - or something similar. That would probably be quite challenging to achieve but I bet they could do something clever to mimic the effect and reduce thermal conduction from hub to rim. Alternatively, do something clever with the hub itself - does that need to be a homogenous material? Could they form some insulating material in to the hub face itself? If they did, would anyone know as the hubs are covered by the brake cooling drums. "More than one way to skin a cat", after all.
Turbo says "Dumpster sounds so much more classy. It's the diamond of the cesspools." oh, and "The Dutch fans are drunk. Maybe"