Open silicon is a big leap beyond open hardware schematics and BOMs that allow people to repair boards, or redesign them to use alternative components.

Precursor is the most open personal computing device that can be built currently.

The comment I replied to was about being "fully open". That indeed goes beyond open hardware. Precursor could go further by at least using an FPGA that has great open source tooling support. It's also not impossible to fab an open FPGA but that's also another hard(and expensive) step.

Precursor goes far, but definitely not as far as currently possible.