When you write »design plan«, do you mean that in the sense of the technical architecture? In this case, Github and Slack (see signup link in my post) might be the best places to discuss.
If you mean product design: we’re just getting started here. We did some greenfield sketching to explore whether it would be worth this project at all, but I’d like this effort to be a lot more research/testing/exploration driven from here on. More on that story as it develops!