The Harpejji is based on the StarrBoard, invented by my friend John Starrett[1][2] in the 1980s,[3] as acknowledged on the Harpejji website[4]. Not sure how the Guardian got to such lengths describing Meeks as the inventor without noticing this.
Here's a photo I took of the original StarrBoard in Gainesville, FL in 1997: https://imgur.com/pilVv8b
[1] https://starrettguitars.com/
[2] https://scholar.google.com/citations?user=q2hIMZ8AAAAJ&hl=en