It is not automatically, but you could assign a shortcut to turn on/off the module.
I guess you are using NLM in profiled denoise and maybe a Nvidia GPU?
If you can avoid NLM it would be faster I guess.
Maybe you can use some technique to avoid NLM and use wavelets. @rawfiner made a nice video tutorial about noise reduction:
https://discuss.pixls.us/t/video-tutorial-about-noise-reduction-with-darktable-2-6/