The issue I have is: you have 2 different materials, that heats up at a different rate. aluminum/alloy, and steel. Also motors have to be designed to run in extreme temps. when metal/aluminum heat up they swell. If there is enough clearance for swelling to occur, then this means when the engine is cold the clearances are going to be at that greatest. This is what can cause scuffing, because the pistons are "sloppy" in the bore...
A motor can last a long time with scuffing going on, but it will shorten the life of the motor. I don't know how mercury can change the laws of physics, or at least to allow for both extreme conditions, without some I'll effects. I sure would like to know how it works if it exists. The thermostats was the solution of the older motors, and a poppet, but if cold water running conditions are 100* the only way to achieve both is design the motor to be ran at cooler temps all the time. That way you could have tighter clearances, but if that motor gets To hot you will stick a piston.........Just my thoughts.
Roy