BTW I’m going to talk in detail about this project spec at tomorrow at HTM Hackers' Hangout - Mar 1, 2019. I’m hoping to clear up some confusion (my own included). You are all free to join, but I know the timing is bad for those of you in Asia (sorry!). But the video will be available afterwards for anyone to watch, so I will do a complete review of the project in my head and you all can post questions / comments here on this thread.
EDIT: I should also note that I updated drawings in my posts above.