Do caster out of combat options matter?

[Vahnavoi]

I don't think the game's own designers should be believed on this point, given the way their adventures are written. They may say that, but it's not apparent in their work.

That's half right. It's true that what designers claim of their intent isn't always reflected in basic rules, and what is in basic rules isn't always reflected in supplementary materials such as modules. However, a dungeon master making their own material doesn't have to go by the last in line: it is possible to stress intent over basic rules, or basic rules over supplements. It would be hardly odd to think 5e D&D is a decent game but the published modules don't live up to its potential.