QwtPolarMagnifier Window not responding

I am using QwtPolarMagnifier for zooming in on my plot. As I am getting a huge amount of data through Wifi, my window keeps getting slower and there is lagging while zooming. I have implemented the QwtPolarMagnifier exactly as the polardemo example. I have threading for some of the processes. AS i cannot remove any objects from main screen. Can you help me find a way to zoom better?

I also saw about QwtPlotZoomer which has a maximum stack depth. Is there anything like that in QwtPolarMagnifier?

The magnifier is a type of zooming, that does not work pretty well with slow replot operations.
So you have to speed up your replot operation or use a different type of zooming - like f.e. introducing +/- buttons.

Uwe