Yeah, I agree, there's plenty in DMG2 that will help you a lot with Narrative and Story Now play, and some bits that seem almost tailor made for it. It is just striking the degree to which a lot of the language is couched in more traditional terms, like the part about collaborative world building. A lot of the ideas will very much benefit low myth play, but its all written as if the GM is 'god of fiction' and is merely delegating some work to the players under his supervision.While not disagreeing with anything you say here, I was specifically referring to the sections on cooperative worldbuilding, asking players questions and building upon the answers, PC relationship structures that anticipated Apocalypse World's Hx by about 2 years, terrain powers as an expansion of Rule 42, alternative rewards as an adjunct and expansion of magic item wishlists, and elaboration of using powers and rituals in skill challenges (a specific exapansion of the DMG1's Say Yes philosophy in the context of SCs). The section on re-skinning the fiction of PC build options is probably apropos here, as well.
I'd say that's quite a lot of actionable content for Story Now purposes, but perhaps you got less mileage out of it than I did.
Honestly though, I was really thinking of the section on Asking Questions primarily in my last post. It is extremely detailed and exhaustive and quite frankly puts most PbtA texts with a similar MC move to shame. Impressive considering this text predated Apocalypse World by a few years (although admittedly not the movement that led to its writing).
I mean, by the time DMG2 came out, we'd already pretty well worked out playing in a fairly narrativist fashion (like we'd moved from XP to basically just giving out levels and treasures as reward/consequence of fictional happenings). I really liked DMG2 though and got plenty out of it, I just largely ignored some of its point of view. It was all pretty much just advice anyway. The "Cooperative Arcs" piece and all the stuff in that 7 or 8 page section can be pretty useful though. I always just hankered to have it all revised in a really pure outright Narrativist version though, hehe.