Oh man, The New Lars was awful. I'm only a casual watcher, but that one really made me uncomfortable with just how skeevy it was to have Steven running around in Lars' body and doin gwhatever he wanted, and how there were basically zero consequences for it.

I mean, I may be alone in this, but I also thought that the guy who hit on Stevonnie was... while a bit out of line, he wasn't actually that bad. It was clear that Stevonnie was uncomfortable with being in a sexual situation, but part of that was because Stevonnie went into a sexualized space, and Stevonnie does look physically mature.
To me, the difference is that the Stevonnie thing is probably meant to more clearly reflect a real-world situation, and is giving a very clear real-world message. However, waking up in somebody's body is a violation that most kids won't actually experience, haha. So while I watch it an am horrified, it probably looks way different to kids, and because it's blatantly unreal it can be set aside as "shenanigans".