I tried dual mining with my Vega FE's but no matter the -dcri the hashrate drop for ETH was too much for my taste and I went back to just ETH mining.
The best performance I got was 32MH/s ETH and ~1000MH/s DCR
With one of my 1080Ti , the best I get for ETH before it start do go down is 37MH/s and 575 MH/s DCR
This is with a tiny OC, max temperature set @69c and using -dcri 45
I will try lbry when the pool pays out.
What pool are you using for Decred ?