I have to say Tim, from my comfy ill-informed chair, that the M-52 in particular doesn't seem a very expensive project especially considering the potential rewards - both research & political.
The whole fleets of V bombers came along pretty soon after, relatively.
Everything I've ever read ( which may be the smokescreen you're trying to penetrate ) was that Yeager came back scared after a hairy near-transonic flight, and told the designer / crew " we've got a real problem here " leading to the use of the all-flying tail for high speed flight, not landing situations.
I'm pretty sure I've seen Yeager say this, recorded quite a while ago, on Sky TV documentaries.
Judging from what I've seen, you won't get far even if you were to interview Yeager now !
He did admit that his depiction in the film 'The Right Stuff' ( which I would be happy never to see again ) the shot of him striding manfully along the desert with the burning rocket Starfighter in the background was " B.S, Son " ! In fact he was badly injured as the seat had caught in the 'chute, then ruptured and ignited his oxygen filled pressure suit - rather than walking out of a shimmering sun mirage at Edwards, he was a heap and in hospital for months.
The ego seems to have exponentially expanded as tempus fugit...