Today, I've had an idea, which is presently waiting to dry so I can evaluate it. I've taken a cardboard box, set on its side so the open top faces out towards me. I screwed two screws into the upper surface, and tied a string of monofilament between them in a hanging loop, onto which I've placed a sprue of HaT Napoleonic Prussian Landwehr. I then sprayed it with the Plasti-Dip.
We shall see if this allows me to get good coverage on the Plasti-Dip without the issue of it becoming stuck to the surface on which the figure rests, and then ripping off the figure during removal. If this works, then coming weeks may see some of these figures still on sprues undercoated with Plasti-Dip so painting can actually begin.