The short answer is that those paints work. I've used the Adhesion Promoter as specified, and it's only been a few hours, but the finish is sturdy enough to sand. And it takes 7 days to fully dry (from the bottle description).
It doesn't come out exactly nicely anodized, as it needs to be polished a whole lot after spraying (not by sanding but by rubbing with cutting / rubbing compounds to get rid of dark dullness). Here is the result in bad kitchen lighting, and I expect it to get better. It won't be uniform--looks a bit aged, with darker outlines by the holes. But I kind of like the effect.
(looks more anodized in person). Anyway, not a walk in the park as far as the process goes but potentially worth it if anyone is interested. Some of the darkness is remnants of black powder coating that I couldn't quite get out (some of it was deep into rough parts of the steel, and in some light it was all sanded off, but in other, there were shadows left).
