I'm vegetarian & eat a fair amount of soya, seeds, nuts & pulses.
I don't keep a mood or food or hot flush diary though so don't know whether there's any correlation. Over the last week, since joining the forum, I've been thinking more about how I'm taking control of my body/symptoms, and I've been eating healthier (including more of the foods listed above) and I am much better now than I was before. But it's not enough evidence to draw on to come to a firm conclusion.
If I remember rightly, the scientific evidence suggests that around a third or half of women might benefit from isoflavones and similar? I suppose you can't know whether you're in which half of the population until you've tried! Good luck