I guess I said some of these things, though much less eloquently, in my own review--the m/m and the het relationship coexist in a pretty weird way. Broster's heart, in this book, is clearly in the Aymar/Laurent relationship, and given how explicit the book is about that, I wonder if it would even have been possible to publish the book if there had not also been a het relationship? Though if that's why the het relationship is there, yes, the inclusion of both relationships is a falsehood, as you say.

I guess it would be pretty easy to read the ending as a set-up for a threesome, or rather, Aymar/Laurent + Aymar/Avoye. Though as Garonne noted, both Aymar and Avoye seem to have pretty conservative sexual morals, so it might be difficult, unless one reads Aymar/Laurent as asexual.

I didn't strongly ship it the way I do Ewen/Keith (IMO it isn't as interesting a relationship in itself)

Yep, I definitely agree. Random other note: I think Ewen is much a better developed character than Aymar, actually.