I've read a lot about Jack Northrop's work on his flying
wings and I think the USAF could have had an effective
aluminum skined version by the late 1950’s if it wasn't so
politically unacceptable to the top brass in the USAF at
the time.
There were two major complaints about the Northrop YB-49’s
that the brass used as an excuse to stop development of the
planes.
1) The bombadiers found it almost impossilbe to hold a
steady course on target because of the hyper sensitivity of
the rudders under manual control which caused excessive
yawing back and forth left to right.
2) The bombays had been designed for conventional bombs of
the day and were not big enough for the new nuclear bombs.
Both of these problems could have been overcome by
inclusion of a autopilot to dampen the excess yaw and
enlarging the bombays.
But the real problem was that most of the top brass just
didn't like the way the flying wing looked. It didn't look
like what they thought a bomber should look like.
Instead they went with the Convair B-36 which in my opinion
was not a very successful design.
Yes the B-35 would have matched the performance of the B-36 with a 30% smaller aircraft on the original specification , which was carrying 10,000 lbs to Nazi Germany from Continental US.
But that job was never needed, and what was needed post war was carrying short fat special stores to Russia.
Those would never fit in the B-35, while the B-36 , designed to carry two 42,000 conventional bombs, could carry short fat fission bombs designed for the B-29/50, and even long fat superbombs that were thought needed in c.1950 with ease (It was the only plane that the Mks 14,17,24 would fit)
enlarging the bombays.
Unfortunately they were in the wings, and it was going to be impossible to make them any deeper, so the suggestion was to carry the bomb semi-externaly, which would have severely shorted the range, which had been already taken a hit by turning it into the jet B-49.
Even so, the only bomb that would sort of fit was the Mk15, a puny 2 megatons, when the B-47 could carry the 10 Megaton Mk21/36.
It would be the late 50s before the USAF had a bomb that would fit inside the B-49, and by that time the B-58, which had three times the speed, 50% more altitude, and the same range, was available.
The Northrop Flying Wing was always the wrong plane for the time (except that of the alternate history universe of Newton Leroy Gincrich's novel 1945).