Definitely there is a diference in missile behaviour between 932.1 and 932.3 versions. 13:45 19th of December, 1972. SR-71 bomb damage assessment flight number one. Battery 261/57.
923.3 seems to be the correct one. The target is far away (over 75km), so in epsilon, the missiles has the maximum elevation for method K, and in beta maximum UPR.
Hmmm, and you said "No change in missile behaviour" - little sneaky developer... Anyway, the + 4 degrees is depending from distance, what else have "Dvina"/"Volkhov" in mind, when determing the degrees of UPR. Speed? If the target is not tracked in distance (which ussualy is not possible under jamming), thus moving of boresight closer or further has no effect.