Even at the maximum aperture of the integrated tap the flow is still very limited (approximately halve or worse). Falls on eg a powerful lawn sprinkler as Gardena Aqua zoom when using 350/3. I find it somewhat surprising that this issue has so far noticed only one other reviewer. Ought almost any immediately noticeable during commissioning.
I've solved the problem as I have removed the cross-flow at the water inlet and also removed the integrated faucet (under warranty loss) with a Puk saw the grid. This is easily possible because the tap can simply be pulled out of the clock. Even after that, the flow slowed down a bit (perhaps 10% less), but this is still bearable.