More varied outposts

The ability to deploy outposts on non colonizable planets that grant other benefits : influence spread, limited production of industry/dust/science or strategic resource gathering. They are removed when a proper colony is founded but can but can used on planets belonging to systems owned by the player but not yet colonized.

These outpost have an upkeep making them dependant of a solid system economy and are unlocked by different tech paths that the direct true colonization. They allow to make usage of yet unavailable systems and planets, while giving players more options especially in early stages of the game. As with current ouposts, we can use additionnal resources ot get benefits from them (leveling up, more output etc)

Without a sizeable defense force akin to real colonies, they make interesting objective to attack or defend with fleets. And their nature could effect the political opinions, giving more tools to the players. 

Finally, each faction may have their own specialized outposts or outposts bonus with different kind of resources used for upgrading them (dust, food, population, influence) following their core "philosophy"