Do the Special Design Provisions for Wind and Seismic supersede methods in the IBC or IRC?

No. The code will always take precedence over a standard because the code is adopted as law. However, IBC 2015 references SDPWS as follows: “2305.1 General. Structures using wood-frame shear walls or wood-frame diaphragms to resist wind, seismic or other lateral loads shall be designed and constructed in accordance with AF&PA SDPWS and the applicable provisions of Sections2305, 2306 and 2307.”