There’s an overview of the end of the ZPM story here, with a link to a reddit thread filled with both angry “purchasers” as well as disappointed “dreamers” like me:

https://sprudge.com/kickstarters-infamous-zpm-espresso-machi...

(I’d got some number wrong in my memory. They were asking for $20k for about 100 machines , and ended up with $370k and orders for about 1500 machines. https://www.kickstarter.com/projects/zpmespresso/pid-control... )