(1)The forfeiture rule shall not be taken to preclude any person from making any application under a provision mentioned in subsection (2) below or the making of any order on the application.
(2)The provisions referred to in subsection (1) above are—
(a)any provision of the [1975 c. 63.] Inheritance (Provision for Family and Dependants) Act 1975; and
(b)sections 31(6) (variation etc. of periodical payments orders) and 36(1) (variation of maintenance agreements) of the [1973 c. 18.] Matrimonial Causes Act 1973 and section 5(4) of the [1976 c. 39.] Divorce (Scotland) Act 1976 (variation etc. of periodical allowances).