Section 46H. Notwithstanding any provision of law to the contrary, incumbents of positions allocated to the management salary schedule, shall be eligible for vacation, sick-leave, personal leave and other benefits, in accordance with rules and regulations established by the personnel administrator, with the approval of the commissioner of administration; provided, that no person who is the incumbent of a position allocated to the management salary schedule shall at any time receive such vacation or sick-leave in excess of the maximum then available to other managers; provided however, that nothing contained in this section shall limit the rights granted employees under the provisions of the second paragraph of section twenty-eight of chapter seven.