Allowing adjustments to seeded line "Non-Recoverable Tax From Payables" in expenditure inquiry

  Adjustments, specifically transfers from one task/project to another cannot be made to non-recoverable tax lines from Payables in expenditure inquiry. Allowing adjustments to seeded line "Non-Recoverable Tax From Payables" in the transaction source form is not possible as the line cannot be modified. We are thinking of updating the transaction source "Non-Recoverable Tax From Payables" to allow adjusts from backend (sql update script). As anyone done the same to resolve this issue?