"There is no way to suppress the calculation of social security tax on the s corp wages so the total tax savings are underestimated."

Is this what you mean: your scenario includes multiple employers (the existing and the proposed S Corp)?

"Their W-2 income from employment exceeds the annual maximum."

Every/each employer will withhold up to the SS wage limit. You treat any overage from having multiple employers as a type of prepayment (estimate and withholding) credit.