Does Firefox do reproducible builds? This bug report makes me think it doesn’t (at least for Linux): https://bugzilla.mozilla.org/show_bug.cgi?id=885777

But maybe they do for Windows/Apple/Android?

It was probably Chick Tracts: https://www.chick.com/products/tract?stk=0046

Have they considered just asking for money? Also getting rid of the giant holes that they keep pouring their money into?

A lot of people love Firefox, and would happily donate. They could also trim a lot of fat at Mozilla quite easily.