If I have to relinquish my sexual function and grow breasts to reduce baldness, then baldness is not a solved problem.
Oh, almost forgot: any messing around with sex hormone levels puts you at risk of depression. That's big side effect #3 (though again, many people don't even notice it).
it's not estrogen where you would expect breast growth (and can't count on any particular changes to sexual function anyway), it's inhibiting conversion of testosterone to dihydrotestosterone which could have that effect, much like you could spontaneously develop gynecomastia without intentionally fiddling with your hormone balance. calling it unsolved sounds a lot like calling the very many conditions with medications that have more likely and worse side effects equally unsolved.
Actually, it is. Reducing DHT levels causes the body to elevate both testosterone and œstrogen levels, via homeostasis. But yeah, it's not a direct effect, and if it's a problem you can twiddle further to make it go away. (You could even do that pre-emptively, though you normally get days and days of warning before breast development actually starts, so I'd advocate the "wait and see" approach.)
> what else would you expect the side effect profile of something mediating the effects of a potent androgen on the body to look like?