Carol's Causal Conundrum: a zine intro to causally ordered message delivery

Wow, it surprises me that there aren't more comments on this zine, which I find a delightful way to present interesting CS topics, detailed explanation and pages full of explanatory drawings that speak. The Zines page [0] mentions the definition of a zine:

> "a small-circulation print or online publication that is produced through noncommercial means and is meant to appeal to a niche audience"

So then, is "causally ordered message delivery", "introduction to choreographic programming", and "Fighting Faults in Distributed Systems" too niche for HN? Hand-crafted with human sweat and tears, no AI. Is that the reason then perhaps for the silent comment thread, i.e. TL;DP, "too long, doesn't prompt"?

[0] https://decomposition.al/zines/

On this topic, is anyone else bothered by the way most home automation software uses MQTT? They splay messages out into multiple semantically-significant topics, which is an understandably attractive idea for writing simple scripts that change when a variable changes and whatnot. But the MQTT spec does not guarantee ordering across topics! So this has a correctness problem with only two devices communicating, never mind three.