I had never considered the bypass hose, but it is logical that the bypass is a problem if you don't run a thermostat - easy to visualize on a SBF with the elbow hose from the intake to the suction of the pump, some water will take the path of least resistance and bypass the radiator.

I had also never seen the restrictor orifices - a neat way to fine tune the flow if you can accept the lower temps/wider variations of no thermostat. The newer EFI vehicles with ECU/ECM have controls set up with temperature set points, like controlling mixture differently until you get up to the programmed operating range, or even going into open loop, limp mode based on coolant temperature (and other things). Smokey showed long ago that the hotter you can run in a controlled mode the more efficiency you can get. Like Weasel said, cold is not always better.