Here?
Suggestions - Faithlife Forums (logos.com)
Book Suggestions for Logos (uservoice.com)
or
Logos Book Requests | Faithlife Feedback
Or are we supposed to email FL at their special request email?
Let me guess...The answer is "E" as in E) All of the above???????
Theo:Logos Book Requests | Faithlife Feedback
For book requests, that is the correct place.
(UserVoice is the old solution we're moving away from. You can always use the forums, but for suggesting a specific book, Feedback.Faithlife.com works better as other users can vote and it consolidates the complete list of suggestions in one place.)