Magnum cooling

They should be fine running more, and that could resolve the temperature issue you mentioned. They are most likely brushless.

Also, I looked for a picture of your shroud in the Torquestorm thread, but didn't see one. How much space is there between the closed parts of the shroud and the radiator fins? Is there any gaps that allow air leaks from the sides instead of pulling most of the air through the radiator?