On-orbit servicing and active debris removal missions depend on rendezvous and proximity operations in which a chaser spacecraft must maneuver in close proximity to a target or dock with it. Autonomous operation around an uncooperative target requires monocular vision-based estimation of the target's 6D pose, i.e., position and orientation, relative to the chaser. Recent data-driven approaches show strong promise but suffer from several limitations that hamper their adoption. First, their scope