The FIRST field electronics are a classic case of an engineering
black box; they tell us what goes in and what comes out, but nothing about how it internally works. As long as the inputs and outputs remain the same, the black box solution allows FIRST to completely change anything inside of there without any other impacts on the system as a whole.
Objects can be black box parts for a wide variety of reasons, including (but not limited to) trade secrets, licensed technology, limited manpower, or just simply because it doesn't matter.
So chances are, you're never going to get any detailed information about the full FRC field for at least one of the above reasons.
And even if you were to somehow acquire full hardware and software information for the FRC fields, what is the real return on investment (ROI) of building this over FMS Lite? Is something that costs an order of magnitude more really going to provide an order of magnitude more benefit? That answer, for a practice/off-season field, is simply no.
Wood/Delta fields and FMS Lite provide the vast majority of the benefits of FRC for a small fraction of the price.