The dynastic prestige system was something that from the very beginning, I wished they would do more with. I'd prefer a general CK thread since people are probably still going to be playing CK2 even after CK3 comes out.
The one thing I have to wonder about the dynasty/house system is if there is a way to break away and make your own dynasty. You lose all the renown and legacies but don't have to deal with your dynast anymore for instance. Seems like getting titles claimed all the time would get annoying if you're not the dynast. Guess it depends on how hard it is to become the dynast.
I think the player is meant to generally be the dynast, but presumably AI dynast will be weighted not to be a tremendous pain in the ass.
oh i dont think thats necessarily true. it will often be true, sure, because most playable characters aren't from a big dynasty with tons of branches, and tend to be playable because they're a ruler with no living ancestors, having inherited from their father.
however there are lots of scenarios where the playable character isn't the dynast, because the dynasty holds tons of different titles all over the place - Jimenez in Iberia, Yaroslavs in Kiev, even minor stuff like if you chose to play as Count Robert of Maine (William the Bastard's son). so the player might mostly be the dynast, and once you become the dynast, i'm not sure how/why you'd ever lose it - your primary heir would generally succeed to your titles and head-of-dynasty. i guess it would possible if your primary title had different inheritance rules.
The devblog describe some ways you end up founding your own dynasty, though, so that's always an option too.