I'm intrigued as to why the intermediary valves are required, i.e. why it's not possible to have a single solenoid valve open to allow air into the pipe? Looking forward to see it all working!
Unfortunately, Covid effectively set us back 18 months. We were hoping to have something to take along to festivals this year, but we've only just got back to work on it and we're still catching up. We'll hopefully have some new videos starting to emerge on Max's channel very soon, and are hoping to have something up and running for next Summer!