I'm wary of any refined soy products. I'm wary of soy generally - even homemade soy milk from organic beans gives me hormone problems - but being at high risk for breast cancer, I limit my consumption of refined soy products to a bit of Perpetuem on my longest runs and on supported rides that I know don't provide adequate protein at their snack stops, and that won't be passing through towns where I could buy a sandwich.
I really never had hot flashes until after my biopsy when I drastically cut my soy consumption. So it might have been preventing them, OTOH it could just have been coincidence.
#1 correlation for my hot flashes is alcohol. Not that I drink much any more (see above).

But when I do, I know about it from the hot flash department.