Stock 73+ BBP/disk master cylinder ok with Ford Exploder REAR disks?

I’ll start by saying that I’ve put about 5000 miles on my car with this setup and I can report that it certainly works…but to this point, I’ve never really stressed the braking system with an emergency stop or a hi temp scenario.

Im replacing the MC this winter and I have a fresh stock one ready to go but now I’m wondering if there is a better choice for a car with rear disks…?

Also, how much weight is there to be saved with an aluminum MC? Is it worth the trouble?

Thanks!