In the story mode of Etrian Odyssey Untold, at various points in the game you get to choose what the protagonist Highlander will say to other party members and NPCs. Obviously this unlocks different conversation options, but does it have any other effect on either the story or the gameplay later on in the game? In other words, are the conversations significant?
While this is by no means definitive, experimentation suggests that no, story dialogue doesn't have any effect; at the most, any effects would be far enough later for the conversation to have been completely forgotten, and aren't overt enough to remind you of the conversation. Labyrinth events will, however, still depend on your choices, just as they do in other series entries.
Judging by this thread on GameFAQs, this lines up with other players' experience, as well:
Pretty sure it's all just fluff. Some of them can be rather entertaining though.