I loved Legion of Three Worlds, but it was a tie in in the loosest sense of the term. I liked the tie in with Renee Montoya and the Spectre, even though it was part of the trend to make the Spectre irrelevant at the first opportunity. And I liked the Rogues tie in because the Rogues are cool.

But none of them really added anything to the main story. Or required reading the main story, either.