I'm more and more attracted to that last option.  #nostache 🥸

I like the simplicity of something like mustache and it seems relatively easy to built various types of Nostr functionality on top of it. Both in terms of: 
1. Fetching Nostr events/media to fill the mustaches with
2. Defining types of "links" that, when clicked, signal specific events to be opened/signed by the native app