Hi, guys!
Like mentioned above-you need to consider the time extra for table selecting as well as the reduced volume. As for low stakes, I wouldn't be really concerned so much with table selecting. If you play 6-max, I won't join a game f.e. that has less than 2 fishes. The more the fish the better ofc, but as a start point-that's what I think is best. I am not sure how much it will increase your ROI and it's really, really hard to say. I wouldn't go that much for ROI though, I will go for $/hour. Meaning that I will focus on choosing games/number of tables that I make the most $/Eu per hour on average.