The tendency in a rectangular timber would be to check on the wide face lowering its shear capacity, although this is seldom pushing the limits. The "safer face" in my mind is along the vertical axis of the beam. A built up vertical girder is fine, but you wouldn't under normal conditions stack a bunch of boards and expect to make a stout beam.
I thought about spiral grain but... it is restricted by grade and shouldn't matter to the kerf IF it is within its limits.
Checks follow the grain, spiral or straight. If you see checks it is easy to follow the slope of grain. I imagine with your dotted line of checks you are seeing checks forming around the weakness at rays. I suspect shear is better in interlocked grain but bending is lower...Again all IMO.
