Hi,
The issue in this case is, that Post Type archive pages are not yet supported – that is why the option says Taxonomy Archives specifically. It was a planned feature along with taxonomy archives, but there were major issues, which we could not resolve yet. Most of the time it worked great, but due to some WordPress related limits it ended up being unusable for some configurations, and we could not risk that.
It is a work in progress though, so it should be available very soon in one of the next releases.