You seem a little confused by the concept of Section 48 inspections. It doesn't matter what faith it is, Section 48 of the Education Act 2005 places a duty on the board of governors of a school that is deemed religious in character to inspect any denominational education and the content of the collective worship. If it's a maintained school, it's the responsibility of the board of governors to arrange for inspection - the actual faith/denomination is immaterial, the Statutory requirement is for all schools of religious character.
In Church of England and Methodist schools, this is called a SIAMS inspection carried out with the input of the Diocese.
In RC schools, it's called a Section 48 (no need for a fancy name) and is carried out with the input of the Diocese.
It's exactly the same in Hindu, Muslim or any other faith school - the inspectors are appointed by the board of governors and usually in conjunction with the religious organisation/faith body that is consistent with the religious character of the school.
As it is, the GAG is largely taken up with staffing costs/ever increasing utility bills/catering and the faith body, where they own or hold the land/buildings, pays for things such as major repairs, legally required fire safety works, temporary classrooms, etc. Schools can also hold private (audited) accounts as result of things such as premises hire, fundraising, donations and legacies; that's the sort of thing that pays for libraries, new play equipment, activities, minibuses, etc.
It's easy to say that government pays for everything in maintained faith schools. The reality is that they really don't.
As a side note, the RC church recognises baptisms made in the trinitarian tradition (father, son, holy ghost), as does the CofE and any other member church/group in Churches Together in England, an ecumenical association. As such, Canon Law means that if a child baptised in that way goes on to take their First Holy Communion, they are Catholic. They are not CofE going through the motions to get a place at an RC secondary, they are Catholic from that moment onwards. Perhaps this might make a difference to some people?