Is implementing Service workers on the roadmap? I couldn’t find forum topics or issues on the topic.
This would enable much faster load times on subsequent visits, less strain on servers.
Browser support seems to be coming along: https://jakearchibald.github.io/isserviceworkerready/
I understand it wouldn’t allow offline usage, since the actual user data still has to come from somewhere and keeping a client side database that’s synced is a whole other challenge.
More on the topic of offline support: http://offlinefirst.org/