IMPRESSIVE--
Thanks for the post! NVidia cards work well with higher "-dcri" values. But, Maxwell (900 series) cards are likely to reach maximum performance at a much lower "-dcri" value than 500. A setting of "-dcri 75" is a good place to start for Maxwell cards.
You're welcome

Radeon 4xx and 5xx cards, 1060 and 1070 cards all have core power more "in tune" with their GDDR5 memory speeds for ETH mining, so there is not much core power headroom left for second coin in dual mining mode. But, 1080 have plenty of core power left so the second coin can be mined very fast

Full -dcri 500 can be utilised and probably more

Somebody with a 1080Ti card could do a few test and see what is happening with -dcri value in ETH + LBRY dual mode. Chances are that card could also mine second coin very fast

Have you tried ZEC? Because from what you are talking, since they aren't balanced (memory/core) like amd and lower nvidia cards, would be interesting to test them on a mining process that requires both memory and core power. Using higher than 8 intensity would be also nice (dunno if this is possible).