While writing up "details" for this project and its "silly long" instructions doc, I added:

...I've just thought of an easier-to-describe assembly sequence that might work. It might cost some flexibility for post-assembly tinkering, but maybe that's a good trade for nearly everyone.

And then I went and tried that. Fail. But failing lead to another idea that worked. So hopefully the "Assembly" doc will get thinner "soon".

(removed that bit from the "details")