That’s nice. But unless SEAD is successful, a BUFF in enemy airspace is *toast*. This is why we have the B-1 and B-2.
Once SEAD is successful, the B-52 can then truck in mass amounts of munitions - but it’s not going to be sent in first to lead the strike by anyone with two brain cells to rub together.
You said “ The B-52 wouldn’t be as much of a threat - these days it’s not a very good penetrator against modern air defenses. It can only be used if hostile air forces and much ground defense has been suppressed or destroyed.”
The B52 is a huge threat and can used well outside an Iranian defensive perimeter.
How does Iran defeat a B52 intending to launch a load of cruise missiles?