I compared the valves and find out that the updated Bosch valve needs 30 - 50% more force to open than the older one.
On top of this there is a restriction (!) in the connector for the vacuum hose.

The result is that the BOV closes too soon, building pressure in the manifold at lower RPM.
In that particular spot (when the BOV closes) the timing is still pretty high causing KR.
The reduction in the connector causes a delayed opening of the BOV resulting in high pressure between blower and TB, and also too much air entering the intake.

I reinstalled the older valve: no more KR and better shifting at high rpm