The golden rule for playing with XML in stardock games is to repeat what they do. Actually making new use of things requires significantly more trial and error and is only possible once you've understood the initial system completely.

In other words, if there isn't already a trigger used for when outposts are created, you have to start thinking about ways of going around that. For example, maybe the outpost creates a resource and there is a trigger for when you first get a resource?

I could be wrong, but I thought they said just ask around the forums. I'd have to go back and watch again to be sure. I doubt they have any intention of posting any sort of documentation. It has always been an un-supported type of thing, with the addition that they will throw in some advice and help on occasion.

They did say to ask around the forums, but I specifically asked towards the beginning if they were going to release any documentation and he said he would, because he had documentation given to those who helped write some of the quests.

For example, it's hard to know how to write a quest and have the sorcerer king get upset when you start throwing up multiple outposts when you don't know what the trigger is.