After testing in an ABO campaign (audiences), using 1 creative in each ad set I have come to a realisation of 'winning' ad sets. Stopped the ones lower than a 2 ROAS, kept the ones that lurk between 3-6 ROAS. I can't leave them running otherwise it will fatigue, right? But I want to scale. Whats the best way with these winning ad sets? ABO's, CBO's?