not helpful so much to the cooling enforcement challenge, but;
more fixed clock challenges.
almost all OCAU run rookie minded comps have had this in place, promotes a level playing field (or at the least appearance of one, to those new to the game.. they soon learn its not always so level lol), it heavily encourages system efficiency and memory tweaking. you will learn more from doing this and the skills you pick up can be applied throughout your benching career progression.
i see the difficulty in some sort of better enforced cooling limits for comps where a clock speed limit is not possible or irrelevant though (like 3d? or comps which cover multiple chipset/CPU types/core counts etc).
its almost in the too hard basket, theres ways around most methods suggested and definitely been ways around the ones being used on this site so far..