Is 'incompatible effect/MP off' temporary?

I am doing a render at the moment and almost the whole comp seems to be rendering on only 1 core..there is alot of Twitch and some wiggle expressions on some flares that may be triggering "the incompatible effect or expression. Multiprocessing is off." thing...

..But does MP then remain off for the rest of the render, or is it supposed to switch on and off as it goes depending on the effects used?

I'm sure there are large chunks of the comp that don't use temporal filters and I could really do with making use of all 8-cores because of a looming deadline!

Question: Is Turbulent Noise an effect that might be a culprit? I've used it as a texture for almost every bit of text in the project!

Cheers for any help.
Jim.

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