Enigma of the Vympel rearward missiles

Folks,

I few years back (1996) , I was very intrigued by a Vympel ad in Russian which depicted a rearward missile being fired from a Su-34 , it had figures and diagrams in Cyrillic.

IS there any progress on the same ? I also remember reading a report that these missiles would not work in practice owing to issues like engine downwash , ejection problems and accuracy issues .

Any updates from the experts ?