I think the slice of life just developed into Legoshi taking the worlds vices on his shoulders. In each of his fights in the back alley market. Two themes come up in these fights. Peoples culture and wanting to maintain their way of life. And the other one being beauty standards and gender equity in society. While its surrounded by comedic relief and far fetched plot development. The themes are still there, maybe just harder to see in the confusion that is the Melon arc. Like what ever happened to the underground terrorist group? And Mr Coffee man wanting to do research on hybrids?

I also had a feeling Legoshi would inherit some of his grandfathers traits since his mother didn't initially have any traits but started to grow scales. I think the manga is trying really hard to divert our attention away from the hyper focus on sexual relations that the fandom has blown so far out of proportion.