Where are Core Storage instructions stored? Where are the Core Storage instructions stored?

In Kevin White's macOS Support Essentials 10.12, White says


  The second partition, occupying the final ~650 MB of the disk is an "Apple_Boot" formatted volume that contains the Recovery HD system. Aside from providing macOS Recovery functionality, this second partition is intentionally not managed by Core Storage, since it provides the software necessary for a Mac computer's ... firmware to understand Core Storage volumes.


If a Mac doesn't have a Recovery HD volume, is it not eligible for Core Storage? 

Will FileVault work? and if so, how does it support encryption during use?
Without a recovery partition you can't enable FileVault 2:

https://support.apple.com/en-us/HT204837


  "Without a Recovery System, FileVault won't encrypt your startup drive."


I'll bet CoreStorage volumes will work, just probably not encrypted ones.