Apply the scriptable object technique to other areas of the level

Extend the Conversation manager to step the text letter by letter in the conversation text with another Coroutine

Expand the event's messenger to support different types of events, passing text, or an object

Add more conversations to the scene for Olaf and Greandal, either by using their collider or having more events (remember to use a grouping game object to keep the hierarchy tidy; I called my grouper, NPCs)

Add some conversation logic to terminate the conversation if the player gets too far from the source