I think that I am finally getting to the bottom reason for my stubbornness on this issue. I had the very definition of SR and GR wrong. Sorry. I think I owe an apology to many people.Flat spacetime = SR
Curved spacetime = GR
I think there was some argument in the early days about which label to apply to non-inertial frames in flat spacetime. But ultimately there's no physics in non-inertial frames that isn't in inertial frames - just the maths is harder. There is new physics in curved spacetime. So it makes sense to draw the dividing line there.