> We do not use any integrated circuits, there is no hiding complexity.
Call me nit-picking but it's not a great idea to "not hide complexity". Largish designs and up are all about managing complexity. It doesn't help you to try and keep everything flat in front of you - whether in schematic or hardware form. The advance made with VLSI design was to use hierachical abstraction as much as possible to keep each level of the design clear and at least somewhat in control. This is about diagrams, consistent logic design families and signals, abstractions solid enough that they can be simulated, repeatedly encapsulated, composed - and so understood and kept in mind by the human designer.
And in this case they probably do. At least the PCB seems hierarchical. But that earlier wording is alarming.
