interesting testing there. nice to see that you used more mounts.
However there is one thing to consider. At different voltages a pump will dump different amounts of heat in the loop.

Also the flow rate-temp graph looks a bit weird to me. I would expect the results from different flow rates to be far less than illustrated (it could be because some of the blocks are restrictive though so..)..

Anyway my cpu temps (fuzion v2) are barely affected from turning the pump down. In fact they seem to improve at some point by a small margin when the pump (DDC3.2) runs at slightly below its full rpm. I know its not a rather restrictive block but maybe its a thing to consider