We're flying essentially the same plane, and we've even had instructors unintentionally eject on the ground. Our solution is that non-rated personnel in the aircraft (except students) will leave the seat pin installed to avoid the risk of unintentional ejection. Pulling the front handle will send the back seat out first, so they just rely on the instructor pilot to do the ejection handle pulling bit. If the person getting the ride ever needs to pull the handle (IP dies suddenly inflight?), all they have to do is pull the pin out, drop it on the floor, and then pull the handle.