afaik the only change in dialogue (that i can remember it's been like 2 years lel) that upon completing the dragoon quests in its entirety (meaning 30-50) before starting HW is that estinien will just refer to the player as an "azure dragoon." i think someone mentioned his slight personality change too and that's also something. tbf i don't see a change in dialogue to be that big of a deal bc really ur not missing anything crucial but i get why people want to have the option but... meh, thats just me.