Probably. But we've never seen that junction up close, so for all we know there is some kind of gizmo that does the same trick. OTOH, the deflection crystal is only necessary for the impulse engines for some reason, probably something to do with the engines needing to use that drive plasma propulsively instead of as an energy source. That conduit wasn't there in Probert's original design. That's what I meant by "via recton." Airplanes can reverse engines too. Application of forcefields over the engine nozzle would suffice for the same effect. The RCS is plenty powerful enough, considering what it has to do. Remember, impulse engines are capable of accelerating the ship to close to the speed of light; an RCS thruster with the output of a Saturn-V engine would more than suffice for this maneuver. The IDF only negates the force of acceleration on objects in or attached to the hull; basically, it imposes uniform acceleration on all objects affected by the thrusters. Turning the IDF off would make no difference to the maneuver, but it would really irritate the crew. So, MY conclusion is that impulse engines are a kind of plasma-dynamic thruster/rocket system--as they have been implied to be since The Cage--boosted with a mass-reducing system either generated by the warp nacelles or the impulse engines themselves. Nothing we have seen is inconsistent with this, but the notion of impulse engines being a FIELD DRIVE contradicts the events of "Booby Trap," not to mention it EXPLICITLY flies in the face of dialog fro STXI, where Sulu says "Give me a five second burst at one quarter impulse, I'll do the rest with thrusters."