I have, in various dispatches, invited my vassals as well. Is it safe to assume they will attend?
I've begun to think of the little buggers as independent NPC's who happen to pay me regency or gold, but really, each should be handled separately and I still worry this will eat alot of my focus in the game.
Especially since the current GM ruling is that there is no diplomatic treaty in place to make stuff like adding law holdings or counting on hardness or advantage dependable.
I mean, if my vassals do not show up at the S&C, then I can't make a single treaty that assumes advantage to some other actor within my domain but will have to spend later diplomacy actions on each vassal, binding them to grant advantage where I need it.
I'll not even begin to describe the issues that crops up if they start resisting this idea. (Which they probably will)