Wow! I’m usually not a fan of the Ender2 type cantilevered printers, but this is a decent size and the board is really quite slick. I’d love to be able to get that board, but while it’s open source, it may be a long while before someone else makes them, if Prusa doesn’t sell them.
In their blog post, the also mentioned making something like a 400x400 printer, but corexy. Possibly another reason they made that board.