Update on my little rig.
Moved from 11 to 11.5 - dual mining XVG - hash rate improved by 0.5 per card but more importantly my stale shares reduced from 6/7% down to 2/3%
Im using bios mod AMD with Blockchain drivers on win10. I did not try the oldkernels command as all seems to be in order
Strange, my power usage hasn't gone up but ETH M/hs has gone by 1 m/hs.
I will try the other one as you mentioned.
Thanks