The higher the better, you get a lot out of cdr gems on 440. For 440 specifically you want at least full 7s and lvl 9 cdr on cod. But 9s on blue skills makes it a lot smoother too.
scratch - purp gale flip - gold gale edge - gold gale cod - gold rage garden - gold QR rain - purp wealth foak - gold wealth seren - purp wealth swap rage on cod for purify for fights that need it
I've played empress in all 3 first hell raids (I have a deathless clown vod on my channel if you want to see), I don't play emperor. And I'm just playing aero for hell brel for consistency; I have done DL valtan/vykas/kuku on ps sh, and also DL kuku on mayhem zerk. Overall empress is really bad in hell but I enjoy it, so will be doing some hell brel with her once I get deathless.