First some words in my capacity as a fan: I have seen/read a lot of Sci-Fi and to me Drive ranks very high in terms of quality.
I think the war between the Continuum of Makers and the Empire is based on a misunderstanding. After all, "RETURN!" is not very specific.
I think, the Continuum of Makers does not want all the rings back.
I think, they just want the box with the heretic spirit and they don't lay it out, because they suppose the Empire knows about the spirit and knows how important it is.