After many tests it looks like these are my best settings: 28ms, 450MHz, 1334mV, target temp 30°C and it runs with 53°C giving in average 43.8GH which means 8.76GH per bitburner xx.

I would like to run 5 miners with 5 different settings to test it out but till now i still wait for the answer if its possible to do without the first cgminer finding all miners and using them all.