Yes you need to have a service worker for that

Yep no way around it for offline web, seems doable I’ll try to get a prototype working.

I was planning on doing that as well let me know how it goes please

Yes. #C87NB2CFN also supports CLJS, and you can implement a fulcro remote that runs on the client. (you can both not use a remote, or use a client-local remote) I already did that for a react-native app, a few years ago. I admit that there almost no docs about it, but it is possible 😉

Do have some snippets, that you can share or have some hints where to look how to start? I found the lack of docs the biggest hurdle