For anyone interested in building one, one of our user's published the project as a complete kit including PCBs, parts and stencil.
See https://aisler.net/p/HVNNCYON
Disclaimer, co-founder of aisler here but not affiliate with the BASIC engine project
I'm fairly good with a soldering iron, but there's several SMD parts there, that would probably test me a bit. If this was really to appeal to low-end hobbyists, it'd all be through-hole parts.
High end hobbyists are already building their own single board computers based on their own designs.
Disclaimer, co-founder of aisler here but not affiliate with the BASIC engine project