For any 2nd coin, I just let it rip and get the Nanos to work as hard as possible
because these Nanos are undervolted using the Heliox rom, and overclocked a bit.
So far these Nanos are heavily stretched but they run cool at 68-72c
So just let them fly....
Did you try play with -dcri too?
At value around 30-35 you will have about the same ETH mining speed, but higher ALT compared to pre-set values
power bill is my major concern.
I am sure -dcri 30-45 will further increase power consumption and heat.