I too am mining CN7 these days, but switched from Cast to SRBminer. The latter is honestly pretty awesome. Stabler, faster, everything. Give it a whirl if you haven't already... Both my Vega and RX 570 rigs have improved.
Im about to swap one of my friends over to CN7 tonight or tomorrow; Xevan profits have dwindled, and hes finally started maintaining a XMR wallet....
He has 6 1080's and a few 1080ti's. Should help with the power bill as well. I miss mining skein, when the power draw was low and the profits were massive....