Two of your criticisms ‒ " difficult to load," and "finicky to move around when loaded because of the small wheels overly responsive to minor imperfections in the floor" are easily overcome. The third, "there is a significant risk of the bike coming off with unpleasant results" is the case with just about all of these devices at this price point.
But even when you get into the very expensive one that was suggested, it's necessary to use a strap to hold the bike into the wheel chock. Some won't, I realize. Just as many, with smooth garage floors won't follow my advice to secure the centerstand with a strap.