Unsolved Threading in the QQuickPaintedItem's paint() - possible?

[SeDi]

Hi,
in the docs I read

"At the moment paint() is called, the GUI thread is blocked and this is therefore thread-safe.
Warning: Extreme caution must be used when creating QObjects, emitting signals, starting timers and similar inside this function as these will have affinity to the rendering thread."

Does it mean it is a good or a bad idea to use threads in order to speed up my pixel calculations? I am calculating Fractals with several hundred / several thousand iterations per pixel. Calculation needs between half a second and 30ish seconds on a decent computer.

I have never worked with threads before, so I'd like to know if it's a dead end before I put too much work into that.

BR
Sebastian