Alright, 24 hours after I moved my display across the room away from the TV (heat source), and I've got zero, zilch, nada residue on the abs. I had a slight hunch that maybe part of the source was the "mesh" armor behind/under the ab plates because it always had a shinier finish than the plates themselves, and maybe it was leaking from them and onto the plates somehow. So I applied a mix of black acrylic paint and sealer to both the plates and the underlying armor, and there has been no leakage from either the plates or the armor itself in 24 hours. This is a huge, huge change from what I was experiencing before the paint application and moving the figure, as I would have to clean it off once every 3-4 hours.