Well it might not follow the 50% increase in potency, but generally phenethylamines are about twice as bioavailable plugged and snorted as they are orally. It might not extend to the DOC class, but I know people who have experience with both nasal and oral DOC who say nasal is twice as potent, and generally nasal and rectal potency of, for example, 2C-Xs is about double for nasal and rectal. I have only ever taken DOC orally so I can't speak from experience here.
Too bad that most phens hurt like crazy to snort.
2cb up the nose is one of the worst things ive ever experienced.
Def not a nice way to stsrt the trip.