Ngl since the serious relationships will only start from book 2, I don't see why there even needs to be an option for the polygamy route with Eldra. Just add a warning that choosing the Eldra route will lock all other romance and flings.Jokes aside I would say it is about consistency just like personality makes certain things greyed out right now a mc who is already with others before meeting Eldra going for more in book 2 for that mc makes sense.While a mc who was with no one and only got with Eldra even when he was a horny teen would be the one who would also not go with anyone else later once he alert has a wife so really all about consistency for the character just like a personality check.
I mean I am usually all for having more choices than less but the whole "Lovers across lifetimes" thing is already there so it makes the most sense to keep Eldra and JDF Mc remain as a "Pure Romance" route.






