The grant, I assume is awarded to the borrower and the borrower under the terms of the grant applies the money toward the closing costs or allows the grant to be paid directly to the bank. If that scenario is correct then the borrower is paying the closing costs with the assistance of the grant therefore you would not discount any of the PPFCs.
Unless the seller is legally obligated to the bank for the payment of the fees you cannot discount the PPFCs. In most cases (terms of the purchase agreement) the seller is obligated by contract to pay the buyer moneys toward the closing costs. They are not obligated to pay the bank.
If the bank applies a lender credit in the 200 series then the PPFCs are not affected. If they pay each line item then the particular item would not be a PPFC if it fell in that category.
The question is. Are you paying closing costs, or are you giving a credit toward closing costs?
If you are paying closing costs then you will pay each line item regardless of costs. If you are giving a fixed amount toward costs then you are giving a credit which must show in the 200 series. IMHO that credit does not affect the PPFCs.
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The opinions expressed are mine and they are not to be taken as legal advice.