While I haven't at all followed these topics closely, my impression is that they have been all over the place. I suspect that some interesting specific themes have been buried in this topic. I would prefer that such instead be given topics of their own.
How about wrapping this one up? Then, if you wish, propose a new topic, with a specific theme to be pursued.
I'll take your word that this is on topic. Carry on.
We've (as in Admin and Adminnemooseus) have decided, however, that there is not going to be a part 5. Next topic needs a new specific theme and a new opening message. In other words, a brand new topic.