Well I picked up this project part done when I bought this house. I assume the king studs are hacked like that because they are only part of a false wall. Non load bearing. After personal inspection, I found that all the visible studs are only extensions of the existing studs solely for making space for the pipe. I'm a guitar maker, not a home builder, but it makes sense to me and is adaptable. My studies on plumbing are what lead me here. The fittings seem wrong, BUT holding a pressure fitting, standard 90 elbow, and a VENT elbow in hand, the pressure and the vent 90 are almost identical internally. Vent elbow being allowed in vent pipe above flood level, I had to know more about why it wouldn't work in inspection. I appreciate all responses. I'm new, although I've been studying for quite a while. I want to learn everything I can