Aquatics OXP - ships, but also adds in one of the Wonders of the Ooniverse!
Curse of the Black Sunspot - mission
Skrounk All-Stars Limited - ships
To Catch A Thargoid (TCAT) - mission
Galaxy 4
Deposed - mission
Love Cats - mission
Trident Down - mission
Galaxy 5
Coyote's Run - mission - affects some of the geography?
Koneko Industries - ships
Resistance Commander - mission - changes the southern edge
Galaxy 6
Draven OXP - ships
Galaxy 7
The Assassins Guild OXP - missions, but also adds in prisons, courts, changes systems, etc.
Galaxy 8
Iron Raven - mission
Galaxies 2-8 - introducing differences from G1
HIMSN - navy
Thargoid Wars - mission
Xeptatl's Sword - space opera mission, starts in G5
Is there anything which should be included in this list? (other than the mention of there being enough ship retextures to allow each galaxy to have different versions of the vanilla game ships).
Galaxy Chart 4 is special for its total lack of Corporate State, Confederacy, Dictatorship, or Feudal systems.
It also has very few systems with a tech level higher than 12.
Something horrible must have happened here in the past...
Galaxy Chart 7 has 2 tech level 15 systems and 7 tech level 14 systems...an industrial powerhouse!
Galaxy Chart 8 has only a single system of tech level 14 or higher. This can present a problem for buying/repairing highest-tech equipment!
Only 5 of the 8 Galaxy Charts have a tech level 15 system.
Galaxy Charts 3, 6, 7, and 8 all have unreachable systems not connected to the rest of the map.
The divide between the systems in Galaxy Chart 7 is know as the Great Rift...fortunately, there are ways to cross it without leaving that chart.
The unreachable systems in 3, 6, and 8 are not so easily reached.
(I personally know no way to reach the ones in 6 without using a Galactic Hyperdrive reprogramming method.)
Beyond unreachable systems, nearly all the Galaxy Charts have choke-points along routes that one has to travel through to reach the end systems, often these are more dangerous (Anarchy, Feudal, Multi-Gov, etc) systems. Plan accordingly!