Hi, John
Print Composer does indeed work with AE 6.1 M020.
We upgraded our Editor and Print Composers from AE 5.3 last year, and have been have been regularly upgrading, so that we are now using 6.1 M020.
You will find when you go to the "Arbortext Product Licensing - License Landing Page" web site that, after releasing your 5.3 Editor and Print Composer licenses, you will be able to upgrade them to 6.1.
Of course, there is a new licensing scheme, FlexNet, which presents new challenges, but which works well once you've worked with it.
--Jack Kulas
LSI, Inc.
Jacksonville, FL