Some implementation details as blue comments on schematics

[rusefillc]

2chan/4chan/8chan have a few pretty complex areas with not much implementation details

Software-defined pull-ups, configurable hall / VR those features could be later taken to other universal designs. How do we reduce magic, add clarity and facilitate reuse?

Do we need to extract new or composite hellen modules? Do we have ways to reuse pieces of schematics just as kicad sheets?