As usual I am fascinated by your processes Aaron. Quite different from mine, so I have an itch to write my own colophon now.
I was also noticed you seem to have a taxonomy ‘series’ I’ve not noticed that else where. I am basing this on the links in the post meta.
I also wonder how you get on moving back and forth from classic to block on your two sites. To my surprise I am almost always in the block editor. Running some smoke tests on Glow Blogs at the weekend I was using classic for several posts and was a bit confused at times.