I think "them" in place of the singular is confusing. Saw a story in paper the other day where a person was being them-d and their-d, so it sounded like they were referring to the person and some other party who was mysteriously never identified. At first I was wondering, do they have a roommate? did I miss that part? until it became clear that Mona, or whatever "their" name was, was NB. The usage was preferred by "them".
My question is if Mona and others finding their identity could involve a newly formed pronoun, rather than taking a confusing one off the shelf. How about "vim" and "vis" or any sound that isn't unwieldy? "I gave vim a birthday gift. Ve liked it a lot and decided to keep it on vis mantle... "