I don`t agree w/ u on that statement. try taking the thermostat completely out and see. I had an approx. 600 horse 406 sbc, it would run hot w/o one. I made some of the washer type inserts to replace the stat, after experimenting w/ diff size holes in it , I wound up w/ (if I remember right), a 5/8 hole in it. Any bigger "more flow" it would heat up, any smaller (less flow), it would heat up. You are wrong on this one.
I've already explained WHY that happens, and it's not the speed of the water flow, it's the pressure increase in the block due to a restriction, just because you don't understand the physics of it, doesn't make me wrong.