Some MC sex scenes could work I think. A good way to implement that is a POV shot. Like for example: sucking Gunnar, the artist could show a camera angle looking up at Gunnar with his dick out. Perhaps the artist could also add a semi transparent mouth/head or hand on the dick. I saw a similar art like this at Hyao's twitter where some translucent hands were groping Logan. That style of MC CG's has potential I think. I also thought of this after discovering POV porn recently lol. I didn't know those existed.
This wouldn't work on threesomes though. But the scene with Korg/Player/Ste could still work since Korg and Ste are sitting side by side. Two translucent hands, jerking them off while the two flex with each other could work as a CG.