What would you like to see beyond what you can already do, i.e. buy a bike (or frameset, wheelset, groupset) and conversion kit?

I think the proposition is an open-source "conversion kit". Battery, charge controller, motor controller, sensors, display, source-code, specifications, etc. Built with some sort of standard so parts are easy to swap/extend. I like the idea

Like it's mentioned in the article the motor controllers themselves are closed source so they have to hack the protocol in order to plug the battery into it.

What if all the software and hardware systems of the bike were open source, not just the battery.

We're only working on the battery, but we plan to open-source at least the app and make the communication protocol extensible with "plugins", in order to let users configure their batteries for any controller protocol!