As I recall you can fill up the rest of the spawn points with things like boss groups.
I would fill up all but two of the allowed spawn areas with defeat boss objectives, and make them spawn after clicking a glowie that spawns after the mission is finished. Its not perfect but should work.
Favorite Hero: Computer (Empathy/Energy Blast Defender)
Favorite Villain: Gimp Computer (Fire Control/Psionic Assault Dominator)
Does anyone know if there is a way to control the number of mobs spawned? I'm writing a story and I need a patrol to contain only 2 mobs (one of each type of minion from a custom group) in order for the story to work.
Any help is much appreciated!
Kuro