Re: Supre Cruise
Yes, SR-71 was a bit different though, because they could exceed M3. At those speeds, the compressor of a jet is almost becoming a drag item, & SR-71 bypassed most of the air directly through some big 'drainpipes' along the outside of the casing. They were essentially running almost like a ramjet at those speeds, with little compression & just igniting fuel in the airstream, running on reheat (afterburner for our left-pondian friends).
The big spiky-things at the front of the Blackbird engines moved forward & rearwards to manage the shockwaves. Unstarts in the intake could be extreme in the Blackbird, and at least one was lost because of this. A pilot's helmet was cracked by the force of his head hitting the side as the aircraft as it yawed during an unstart.
Concorde got the sweet spot of speed & performance. Trying to go faster would require more exotic fuselage materials & getting certification for safe operation faster than M2.abit with paying passengers rather than steely-eyed fighter jonnies would, I suspect, have been too difficult & costly - the Americans spent 1BN USD developing a faster passenger jet than Concorde & gave up.
As someone else says, there's tons of info on pprune, & there's also the heritageconcorde site, & several really good books, & the itvv.com Concorde flightdeck DVDs, which after many years are about to stop being made. If you're going to buy anything, get the itvv dvs.