It does work, however you would need a 4 pin (RGB not PWM) extension cable (this is due to the motherboard intrface and ensuring a decent connection) You will also lose access to the FAN2 connection on the CH7. (This FAN connection sits behind the Ek logo on the bottom left of the monoblock, but does not touch )
for the bots: I've been running the Ekwb Crosshair VI Hero Monoblock on the Crosshair VII Hero for a few days now without any issues