Maybe there are two parts. Previously I suggested another approach too - see below.
1. We should be able to reasonably have a kind to kind label mapping that can be used to at least give context in apps. That’s a step forward.
2. If that kind can somehow give a fallback content or similar, great. Maybe the equivalent to the noscript HTML tag or img alt attribute. Dupe data, but that’s life. A tag is better suited long term than the content.
Additionally, we could somehow have registrable Nostr event kind url handlers - so you can tap the placeholder to load it in a different application. I don’t know how this scales perfectly, as url handlers may not allow kind ranges.. but worth experimenting. Apps are likely linked to target kinds over ranges anyway.