This is a super-impressive module, which I backed during ZineQuest #3.
The writing is crisp and the layout is designed to be easily usable at the table. Without spoiling too much, the adventure includes some faction tensions and most encounters can be solved non-violently if the players are smart.
I am currently adapting The Vitacernis as an adventure location in a Hex-Crawl run in Knave.
It's really easy to do if you allow giant trees in your world (thinking of Troika! and Fronds of Belevolence), so take a look into it even when looking for sweet adventures for other OSR-rulesets.