Hey Tator. Used to live in Ankeny.
From what I know boiling the full volume in general is better, but it will affect the hops utilization so you will probably want to adjust them. Also adding some of the extract later will give you a lighter color and potentially better flavor. You could try emailing AHS and asking them,I've found them very responsive and helpful
Bottled and disappearing: Pale Ale/BM clone/Dbl Choc stout
Kegged: BM clone/double chocolate stout
On Deck: Hefe