Seems pretty promising. The language looks clean which I can't say for some of the alternatives.

The thing that I find so challenging about these types of systems is scaling up the richness of the playback.

Very quickly I find I need to integrate animations, lip sync, vfx, timed event triggers... For that you really need some kind of timeline. Delays don't cut it. So then these clean text driven systems are at best an early step in a large process or abandoned for a more integrated solution.

But I really do long for the ability to import simple narrative scripts like this even in a full production system.

One of these days I'll try to build the high production value system in a way that keeps both the full, in editor, narrative graph and the simple narrative script files alive and synced.

I actually plan to tackle the "graph in sync with the narrative script files" in the future, just not the focus yet :)