Does the "Layer Collision Matrix" affect triggers?

I can’t see this documented anywhere, and as far as I can see, it doesn’t. Am I missing something? A checkbox somewhere?

I’m using it so that only objects on a particular layer can activate a trigger. I’m aware that I could do a layer check in onTriggerEnter(), but don’t think it should be needed, since it should only detect trigger entry by object on that layer.

Right now, it ignores the matrix. Is this expected behaviour?

I do a test in 2D and the Triggers works fine for me with the collision Matrix.
But you need at least one rigidbody in one of the object to make the trigger works.