Here's a prototype of the pirate systems from my campaign. I originally had them "south" of the Frontier but decided they would be better served "west" instead. Since the Star Devils are the reigning faction, it just made sense to have the entryway close to Zebulon since that is their "first appearance" in the Frontier.
I'll submit a detailed description of each system (via Zeb's Guide details) as I redefine each system and update the map. I labelled the Frontier systems according to Zeb's map for continuity. I am using the Zeb's map as a starting point as it is the most detailed published material out there, and anyone else can edit it accordingly to fit their campaign later.
Note that one of the Formad Cluster binary systems is the "gateway" system into the Rim (capella) which leads to Zebulon. Sundown is a secondary inlet to the Frontier...while Spacefleet has the sole knowledge of the Frontier route to this system on the UPF side, the pirates also use it despite any lacking interest of the scientific outpost ont eh surface as an entry way into the Frontier (which can lead to all sorts of interesting conflicts later).
Also note the "trinary" system, containing three stars and a system of planets.