Notwithstanding section 959AF(3), an assessment or amended assessment, as the case may be, made on a person shall not be final and conclusive where, within 30 days after the date of the notice of assessment, the person -
(a) requests a mutual agreement under an arrangement having the force of law by virtue of section 826(1) between the competent authority of the State and a competent authority of another jurisdiction, or
(b) submits a complaint on a question in dispute to the Revenue Commissioners under the European Union (Tax Dispute Resolution Mechanisms) Regulations 2019 (S.I. No. 306 of 2019).