I've noticed the following behavior several times and I found it quite annoying. Many times when I select 2 vertices and press J to cut a set of edges through, it's not going through the expected shortest path.
The correct shortest path is the yellow line. What is the logic Blender used to determine it to place the vertex in this position? Since both the start and end vertices have the same Z position, I would find it more logical if it didn't take a "random" z value and just use the same z-value as the selected vertices. How do I configure Blender to make sure it goes through the shortest path?
Out of curiosity I also tried removing one face to see how it behaves in this example:
Anyone any idea?