Not to bump my own thread, but I've updated the diagram again - was
able to compress a lot of vertical space for the main diagram, and add
some informative notes calling out interesting/important aspects.

It's not (just) that I crave attention that I post this, but I really
want to make sure that there's nothing wrong or misleading with the
diagram. Having an incorrect diagram (*cough* ilias *cough*) on the web
would be far worse than having no diagram at all.