That's a bummer. It was one of my favorite parts of this game :p
I did manage to get a PDF of the Companion booklet, so all is well, but I think it'd be cool if those rules and procedures were available again in some official capacity imo.
Viewing post in RELIC v3: An Analog Adventure Game comments
The Monster Overhaul by Skerples has a bunch of stuff about eating monsters. I got most of my ideas about it from his original Monster-Menu-All PDF on the subject: https://coinsandscrolls.blogspot.ca/2017/08/monster-menu-all-part-1-ad-monster.html