I've previously noted that, AFAIK, this characteristic is practically a distinguishing feature of Abies firma. I've never smelled any fragrance from it. Even after boiling some branchlets for 20 minutes one winter day, there was hardly any odor released - maybe just enough for you to know it was a fir. OTOH, boiling the same mass of Abies concolor needles filled the entire house with the characteristic odor of that species. As far as I've been able to tell, even other members of the same section like A. chensiensis, A. recurvata and A. pindrow have a fragrance. (I arranged those in ascending strength.) Perhaps subsection Firmae (http://www.conifers.org/pi/Abies.php) is the only one with the feature, but I'm unlikely to be able to test A. beshanzuensis for quite a while.

HOWEVER, I was out watering on the very hottest day we had last week, when it was near 100F, and I grabbed a needle and crushed it. For the first time I was able to detect a slight odor - without boiling! Maybe when it's that hot, whatever small amt. of fragrant oils that are present were more readily volatilized.