Here i attached an example of rig made using in win 303. You can see that the sleeved cable of 24-pin that attached on the motherboard need to have a little bend right after out of the cable management hole as the hole is quite below the pin slot. But yours, it seems really come out straight and did not have to be bended. So how do you do it ?
Ah, gotcha... there is a bit of trickery in my photo there I think. I ran it through that same pass through hole that you've used, but the cable did bend and twist as it went through.. you just can't see that because it's behind the reservoir. The cable combs helped keep it straight coming out of the 24-pin. Also, my 24-pin is lower than yours, so that allowed me to do it. I recall it took me AGES faffing about to get it right though.