The universal limpet controller would like to have a word with you. Size 7 used to be unheard of, until the T8. But that one is probably the xact reason why the Corsair doesn't get a size 7.
I’m aware of the controller but size 7 and 8 slots are supposed to be for large ships, otherwise what’s the point of them? Or maybe a specialized medium ship like the type-8. Not on a medium multirole. If the corsair lost two size 6 internals in favour of a size 7 it would lose a significant part of its multirole aspect. Besides, it would then completely eclipse the type-8 in every way.