CO does not reduce temps, just lets CPU boost higher/longer for the same power target.
I have -30 aswell but with a -150mhz offset for more stable clocks and less voltage spikes.
I believe/hope we are past that development fase.. you only need one fan if using a tower cooler and there is always the silver soul 135 with lower height.
The case was supposed to be sent on tuesday and since then no news. I can understand if some problem came up and I am in rush at all, but having no answer to my messages makes it look bad.