We do not feel this at all. Flavor comes mostly from the terpenes in cannabis. To enjoy the flavor the best it really comes down to the proper low temperatures. The hotter the temp, the more the fats and lipids will vaporizer, changing the flavor.
We feel small rigs are a fad, and while for sure a challenge to make, a normal rig will give you the same great flavors as a small rig.
The volume of air inside a nano, small, standard or even a large bong is kinda small, and the air is moving so fast from the front of the rig to your lungs we feel this is negligible. The idea that a small rig gives better flavor can be argued like anything, but we feel it is the reality that a larger rig is hard to make, so the artist says hey, it works better for this, this we feel is marketing and no science behind it when this small of volume is considered.