The official with whom the return is required by subsection (f) of section 2136¹ to be filed shall determine the allowance or disallowance of all deductions claimed. The determination, unless suspended until audit, shall be made within six months after the claim for allowance has been filed and, if not so made, shall be made within such further period as the court, upon application by any party in interest, including the personal representative, shall fix. However, the court, at the request of the fiduciary at the audit of his account, may determine and allow, as deductions, all properly deductible credits claimed in the account or allowed at the audit without requiring the filing of a separate claim for them, and the court may then fix the amount of the tax and decree payment of the tax. Deductions exceeding one hundred dollars ($100) in the aggregate shall not be allowed by the court unless the Commonwealth is represented at the audit by counsel or unless there is proof that the register has had at least thirty days notice of the claim.