It’s a small Wye just to show it’s possible to include one, even with O-72 curves. I also did a version with a 28” turntable, no roundhouse though.
The thing about reversing loops is a lot of times the same effect, trains going in both directions, can be achieved with dual mains. Mark’s design could be done using dual mains instead of reversing loops, but the Parson’s area would have to be expanded and then reach might become a problem for him.