As a working Production Designer, you have it entirely backwards on the scouting front, as far as which crew to bring along. A Designer has hundreds of logistical and creative considerations to factor before they can sign off on a location. The number of times indie productions try to court us by choosing locations before we've even signed on, much less seen the locations themselves, is baffling. As if that's appealing! A DP can work from scout photos (that's largely all they ever do on bigger TV and film anyway).