In mine (original CM690 dominator from last year), with my modular psu, I was able to do decent cable management, barely getting the side cover on over the side where all the cables are pulled through, but with brute force, I was able to fully clip it down. Right now, I've replaced with a non modular psu and because of the extra cables, can barely get the side cover on. The bottom clips won't meet, there's a bit of a gap, but the 2 cover screws are holding it. Inside the case is ok but not as tidy as it was with the modular psu. Anyone else have this issue or did you find a way to get really clean cable management?

As long as you aren't doing anything ridiculous, you aren't going to run into any issues 