I recommend using ASCE 7-22, which is now consistent with the 2017 edition of SEAOC-PV2. And I suggest reading all of Chapter 29 of ASCE 7-2. 2
The prescriptive pressure coefficients are plotted against the NORMALIZED effective wind area. This is not the same as the effective wind area. The normalized EWA is determined by the formula in ASCE 7 and reflects the building dimensions. The effective wind area (EWA) of the PV module reflects the load sharing of the array. If each PV panel is mechanically anchored, then an EWA of one panel is appropriate.
The air pressure equalization factor (ϒa) shown in the lower graph is only used when the PV panels are parallel to, and 10 in. or less from the flat part of the roof. The minimum space between panels in both directions must be 1/4 in. Often the clamps between the panels define that space, which usually is at least ¼ in. In that case, external pressure coefficients for the roof cover may be used, and reduced by multiplying by ϒa.