Hi, OP here. I'm glad you enjoyed the writeup.

Amateur...you're probably right. It reminds me of my home improvement project I've been working on this evening: interior painting. My ceiling lines are probably perfect to houseguests (if they notice at all). But if a professional painter got up on a ladder and looked closely, he'd probably shake his head and chuckle.

As for InDesign and EPUB, I've found the auto-generated output not up to the standard I was after. Worse, I've seen output differ between InDesign versions, which scared me.

I have an acquaintance who works for a "Big 5" publisher, and he recounted their process to me once. In short, the indd file became the source of truth. They would generate an EPUB from it but then hand edit it for many hours to bring it up to their house style. If there was a text change (rare in fiction) they update the indd and EPUB separately. Going back to the Word file is basically non-existent. If the author, copyeditor, proofreader had more extensive changes (like a full revision), it was close to a brand new publication.

The visual styling from the word processer isn't interesting. It's the "tagging" that paragraph and character styles bring that's helpful. It's not dissimilar from an HTML class, which scripting can transform into truly semantic text. I hope that clarifies some points. BTW, it's pretty cool to hear from people in the real print industry. I'm always fascinated by their workflows.