The Big Question: First or Third

[Kaden]

There's no real discovery, though, in the third-person omniscient narrative.

Definitely doesn't have to be omniscient. Look at, basically, the whole "whodunit" genre. Most good plot-twists happen because you're lampshading the presumption of omniscience, imo. If you keep knowledge of the world relative to the character you're focusing on, you don't have to make everything transparent. You could do something like have Character A see Character B as some kind of extremist bigot until the end of the book/scene/act you kind out that his whole family was killed by... I dunno... koalas. So all the previously mindless hatred and violence against koalas seems much different when the reader thinks back on things that have already happened. It's kinda like using first person, but without using first person.

Definitely agree about engagement, though.