Rather than a bestiary BOOK, I would prefer a collection of sheets: stats on front, and either blank on the reverse OR a full memo of how each of the adversaries Fell Abilities applies; with any other incidental detail (quote from text, regions where this adversary might operate, a bit of history, etc etc ).
I know that some folk prefer books, but the sheets could fit inside the Starter Set box and of course both updates and new adversaries are easily added; put into any order the L'M wishes; and can be shared with players when appropriate.
It would reduce searching across different texts for full details when designing games too. And future proof the arrival of new adversaries.
Yes, of course I can print individual pages off and protect them. But I like the look and feel of a professional product. It's why I paid more for the Collectors Edition. In fact I'd probably buy BOTH a bestiary book and a bestiary collection. But I'd use the sheet collection more readily. Hey, I can dream, can't I?