You seem to be confusing what was hoped to be achieved by the end of a development process that never happened with what actually saw the light of day. In the real world, the SR-71 had a slightly higher service ceiling than the XB-70. 85,000 feet compared to 77,000 feet. Significantly faster? Not in what was actually built. Better EW suite? Not developed and implemented into what was actually built. Remember, the program was cancelled in '61, definitively so in '62 despite the best attempts of LeMay and Congressional allies to reinstate it. What was built was never going to be developed further, being relegated to general high speed aeronautical research.
I mean, c'mon, making claims of paper aircraft? There is a long history of designed but not built aircraft with incredible paper specifications but that never were built or if built, never achieved it in the real world. One can claim anything about such fancies.
Furthermore, substantiated claims about intercepts of the SR-71 and if they were achieved or not are out of the public domain (still). Unless you are privy to such classified information, you don't really know and I don't really know, one way or another. There is only rumor and web tales. I'm partial to the Swedish stories about achieving radar locks on SR-71s during the Cold War. Did they really? No one with authority is talking.