I started a new playthrough and talked to alot of NPCs.
I like the camera zoom in and UI fade out during dialog. Immersive. Good stuff.
But the zoom in and out gets distracting when you want to talk to the NPC more then once. Its visualy unpleasing and busy.
My suggestion:
Keep the camera zoom in after dialog (so he can press A again and start a new dialog if he wants to). Move the camera out once the player moves away again with L. Or zoom the camera out when the NPC has nothing new to say anymore. That way the player gets a hint not to press A again and getting a repeat dialog sequence.
More immersive + functional without beeing intrusive.