While reading this, the hair brained idea of a dip switch (or similar) popped into my head. Probably too many chances for error in the settings with dip switches (having two modes selected at the same time). But, the wheels kept turning and I found a 6PDT switch at Mouser for 89 cents. They have a few more to choose from while keeping the price under $2 or so. (Not to worry, I didn't order any. )
I think having the separate PCBs is just fine and will probably never do anything different (no 6PDT switches). It's just fun to consider the options and fiddle with the schematics. Also helps in learning a thing or two and I usually figure out how to do something new in Diptrace each time if I fiddle with it.
I still haven't perfected silkscreen info and getting it properly placed on the PCB, but I do like your suggestion of marking the PCBs with the assembled board type. I'll work on that one some more, maybe something useable will be achieved.
The PCBs I have fit my needs for now, but I plan to modify the design files for a couple of different types of PCB for more practice and learning and will post the complete files when finished, tested working properly. This is a really fun project and great learning experience.