Every now and then you come across a keeper - I'm having this one, Walter!
The main purpose of the riving knife (apart from acting as a mounting point for the guard) is to prevent the kerf closing up and jamming the wood on the blade. If you are not cutting all the way through the wood then the kerf cannot (or at least is extremely unlikely to) close up so that should not be a problem.
Ideally you should be providing some alternative form of guarding when using the saw in this way but that is up to you, it is your safety. Just remember to re-attach the riving knife and guard before you go back to normal cross-cutting or ripping.
Walter
Oh, and by the way, I've recently bought a 16" bandsaw.... standby for questions
I have read most of the manual though