I don't see any way to reverse the direction the train is coming from. It seems to me that this intersection should have no more functionality and traffic capacity than this full R30: https://hub.coigame.com/Blueprint/Detail/1398 It looks pretty good, so I'm going to test it anyway.
@Malibu2, I found having a u-turn (IE; roundabout) added congestion with the extra merge wait points, and also slowed down the path-finding. An intersection is the chokepoint for rail traffic so best to minimize merges and lane changes. You can add a u-turn overpass just outside the intersection if needed, with waiting space for the trains to wait for merging with oncoming at-speed traffic. This design is different from #1398 if you look at the inside lanes - every lane has the independent option to go right, straight, or left.