But from linearized gravity concept (where curved spacetime = flat spacetime + spin-2 fields) which you are familiar with in our discussions in the other threads. FRW metric can be modelled as Flat spacetime + spin-2 fields. Since the flat spacetime has a version called Milne universe. Then FRW Metric is really just Milne Universe + Spin-2 fields. Do you agree or object to this and why?