Gods of the Gaps
Those systems colonized by the Starlords, but never reclaimed by the UFP, have come to be collectively referred to as the Hinterlands. This despite that fact that some of them are quite prosperous and independent. However, the only real constant between the Hinterland colonies is their disparity, and a fiercely independent streak.
Given that were colonized by different interests, for different purposes, the state of development of individual planets varies wildly. On the whole, they are less populous than UFP held colonies, and certainly less technologically developed than members of the Antric Enterprise. Again, generally speaking, technology has taken on a very utilitarian edge. Ships are simple, sleek, and largely without frills. Life is a mix of high technology, duct-taped and rubber banded together, and sweat. Imagine the Star Wars galaxy.
The Hinterlands are made up of somewhere between 100 and 200 systems. The exact number seems to depend on who you ask, and when you ask them. New planets are still being colonized, however, so the number is tending to grow. If you can think of it, it’s somewhere in the Hinterlands.
System seem to make up the autonomous unit in the Hinterland. Some groups of systems are still tied to Starlords, but the majority of the Starlords lost their grip on their colonies following the war with the UFP. Typically, the planets have their own internal issues to deal with, and that occupies the bulk of their efforts, and limits their ability to form meaningful larger entities.
The bulk of interstellar economy and travel is centered around resource export, both to the UFP and to the Antric Enterprise. A fairly constant stream of refugees comes from the UFP, and all sorts of unimaginable technology from the Enterprise.