We recently changed our stratergy in this regard. Now we publish on checkin, and then have a custom expression in the promotion workflow that "republishes" the default reps, just for the promotable drawings in the PN baseline, assuming the promotion was approved. Before we were publishing on checkin and promote which was total overkill. We map LC state to a CAD parameter which is then shown on the drawing. Hence the reason for republishing, so the state can be updated.