Initiative Switchover can happen to the Soviets between
October 1 1942 and July 1 1943 whenever the German score
is 10% or more below the German High Water Mark score.
If I understand correctly there is two way to manage Victory points. One is to trying to achieve highest victory point regardless of how deep penetration's to Soviet. But to delay initiative switch a German player can also choose to limit its advance to a line where he can keep the 10% VP margin longer by defending the line longer. I mean The deeper you move the more you risk early recapture of Victory point places so the switch will be faster.
On the one hand highest victory point is better for the endgame. But is there any advantage to delay Initiative shift once Germans benefit from all bonus VP by early capture.
Also I cant find a reference in the Manuel but lets say I captured Leningrad. But then Soviets surrounded Leningrad can German Troops drain supply from Finnish supply system. Or German troops will be surrounded de facto.