"The AF&PA NDS fiber stress in bending (Fb) design values for sawn lumber wood studs resisting out of plane wind loads shall be increased by the factors in Table 2306.2.1" (emphasis mine). The code gives you no option for taking a more conservative route. That means a 1.5 factor on 2x4s and 1.4 factor on 2.6s. Now, there are various restrictions on this increase (spacing, sheathing), and it's in lieu of the 1.15 repetitve member factor, but it does exist. It is, however, not a substitution for using MWFRS where C&C would apply.
Jordan