Thanks so much for the deep dive! I really appreciate you taking the time to write these lengthy critiques. It's a real gift to the community, and it's obvious from your entry that you know what you're talking about. I'm honoured to have made the list.
You raise some really good points about the layout. You've given me a lot to think about. I was locked in on the idea of a little booklet; I hadn't thought much about it as a series of single pages. I suppose that's how cell phone readers will encounter it as well. Lots to think about...
One thing I'm happy to report is that the font size (even legal) holds up pretty well in print. The back page white-on-black text is maybe on the edge. Perhaps I should rewrite some of these Random Encounter entries, try and free up some more room to expand the font size there. More to think about!
Re: the apocalyptic nature of the module and its effect on campaign vs one-shot play, that's an insightful note. My intent in having the Old Ones move at half-light speed was to make it a slow-moving apocalypse. With ~5 light-years between nearby stars, the Star-Saddled Pterodactyl riding PCs can flee at FTL speeds back to civilization, leaving the freed Old Ones as a looming campaign BBEG/consequence. I had a lot of space to make this explicit, and I totally did not do that. I think fixing it in the next version will really help the module, so thank you!
Again, it means the world to me to get a long review like this. I'll try to pay it forward by writing some big ones myself. Good luck!