Quick overview about what can player expects from a faction outpost.
Outposts are special locations that are guarded by one of two rival factions in the world.
If you are not loyal to a faction, units will attack you. Of course you can benefit from it. In some fallen units, you can find special keys that unlock locked crates in the Outpost, in which you can find very rich and rare loot.
If you are loyal, you can trade here with merchants who may have a better or special offer.
Units in outposts are automatically replenished by incoming transports if they are depleted (for example, when you attack them). You can shoot down the flying transport, so there will be no replenishment of units. If you attack the outpost long enough, the second state of defense will activate and the special transport will drop war drones, which will immediately begin defending the outpost. If you’re not equipped enough (armor, lots of ammo, and good weapons), things probably won’t end well for you. However, if you repel the attack, you can also loot the drones.
Attacking also earns you loyalty to the opposite faction.
Outposts are a very rich source of weapon loot if they are your enemy faction.
If you don’t feel like raiding the Outpost and you’re not really faction loyal, you can find a special merchant nearby who will arrange loyalty to a certain faction for a fee, so then you will have free access to the Outpost, but only for a certain period of time, as loyalty gradually decreases over time.
(Spoiler!) Outpost crates can contain a special document that can be sold very profitably to the opposing faction. In dead units you can find a faction items that can be sold to those traders as well.