"Either Innovation or the CPA firm is trying to claim that info is proprietary."

Your client is their client. Your client submitted the raw data to that process and the forms were submitted on their behalf with their approvals. They should not accept that answer, because they are the responsible party in the eyes of the IRS, if there is an inquiry. The math is per the IRS. There is nothing proprietary about following regulations. Their system can be proprietary, but they should be able to provide shareholder/officer and/or nonqualified wage info relative to what was applied for.

If not, how do you know they didn't just throw a dart at the wall and submit that value?