One more suggestion regarding CS rewards.
On last sprint GM Boxes as CS rewards were introduced far too early in the game.
There were people running with exc Bone Blades+3 opts and 380 set items before K5 goldes were even released. When you see someone with 380 exc weapon at the stage when you can't even get exc AA (because it is not available in game) it feels pointless to play.
I would suggest making the GM Box reward available only after 2nd stage (10rr). You can think of some other reward in the early stage instead, but I think winning CS gives you enough advantage early in the game even without exc 380 weapons.