You know what's really interesting? You're saying that "his sensibilities just do not translate to long-form storytelling", yet I've noticed he's one of the few directors that can handle and deliver a third act of a film exceptionally well, the lack of which is something that plagues so many movies.
Like I was watching the director's cut of Watchmen and was like, first act: "ok, quite good so far", second act: "yea, this is really really good, no... it's great", third act: "holy f***ing s**t this is fantastic". And that's a film that was deemed un-filmable and Snyder even changed the Moore's ending.
Some day I must watch the longest cut.
BvS UE, another 3 hours long film with so well-controled build-up and such a cathartic finale.
Man of Steel is not only superb overall, but has one of the best third acts ever. I mean ever, a pure blissgasm.
Zack's style is quirky, but he definitely has no problem telling a long cohesive story, rather the opposite, his 3 DC films are the best stuff since The Dark Knight. (Still haven't seen the Rogue Cut of DofP though.) Plus I've noticed one important thing, the more I watch his DC films, the more they keep giving. Which is exactly the opposite of when I was trying to rewatch some MCU films, old and recent, and they felt so flat I didn't get past the first hour (sometimes even 20 minutes) with any of them. I must rewatch X-men 1 and 2 to see how they perform in this regard.