Is it possible?
Not directly - if you can convert ePubs to Word docx format (e.g. by using a software like Calibre), you may add them to the library via Tools / Personal Books.
Is that a lot of hoops to jump through?
This depends. The technical process is rather straightforward - as long as Calibre can read the ePub content (which may be a DRM issue) it can convert into several formats that Word can subsequently read and then save as docx. The result would be something like a Vyrso book - Logos automatically detects bible references, other than that it's an electronic resource you can read and search in with Logos.
The work starts if you want a more complex book to work like e.g. a commentary so you'd input tagging into the docx to have Logos flow it with a bible. And footnotes are a pain. And when you want references from your PB to link to your other resources in Logos, you'd have to input those links. You can check out the Files forum for examples. (One side effect for many PB creators is they learn to appreciate the work Logos does in tagging these books, which makes them a bit more expensive than a simple ePub or Kindle version)
Thank you, Sir.
You're very welcome!