1. AMD cards always handle dual mode better than NVidia. Especially 290(X)/390(X) cards, they are the best. RX480 is good too. Other cards are not so good in dual mode.
The best are Fury and Nano (29.6 eth + 1186 sc)
290x has only 29 eth + 586 sc
but Nvidia more profitable on LBRY (1070 get 312 mh, Fury get 252 mh only)
Unfortunately, there is no way to get 0% drop on ETH if you mine ETH+LBC. Why? See item #2.
Fury not drop on ETH at dcri 30