...yeah, you are....

The prop disc is mostly air - 91.3% of it in this example. Even if the exhaust stream was a constant flow (which it is not..) 91.3% of it would miss a prop blade regardless of the RPM. Because of the slender design of our prop blades, this system should have a good chance of shooting the majority of the exhaust through the propellor disk without impinging either of the blades. ( now if was a household fan blade, then yes it would make a heckuva mess...)

Anyways we are just talking theory here. It is not a critcal issue one way or the other. It would be interesting to see some real world results (although I'm encouraged by the one users comments..)