Everything changes everything in the body all the time. We only care about when things change in certain ways for certain endpoints to certain degrees.

So, what are some hard health outcomes we can measure? What does the literature say about them as isoflavones are increased? Anything significant?

For example, does erection strength decrease when men eat 300g of edamame daily or something? Show me something.

I have the same questions about meat and dairy. Google "meat estrogenic" and "dairy estrogenic". I don't consume either so I haven't cared to read them but you can find papers talking about it. Without looking further, you can't tell if it's something you should care about or not.