SR71 flies high enough that remaining energy is not sufficient to close with the target from the rear. You can 'easily' place a missile ahead of the plane and allow the SR71 to fly into the intercept point however - the difference between being run over by the bus, or trying to catch up with it on foot...
The Dvina has enough energy to catch a rear-quarter ground attack or bomber which is subsonic or just barely supersonic though, so the receding target fuse-delay optimisation is useful against these targets.
Historically the SR71 wasn't hit by any of the weapons trained on it - I'm not sure how many were fired, as opposed to out-of-parameters and not launched, but there wasn't much that had a reasonably large window of opportunity during the cold war, and Dvina is one of the lower capability weapons - but it was the best that Vietnam had available... so it was the weapon of choice.
With IADS, the Dvina should be capable of guiding a weapon to within fusing range on an F117, how well it will cope with also detecting the target in a complex environment and with little/no cueing I'm unsure, but it sounds tricky.