In thinking about BO, I keep coming back to my thyroid medication. I take prescription natural thyroid made from dessicated pig thyroid glands. The pills are standardized so I get a consistent dose of thyroxine in each pill. The thyroid gland makes thyroid hormones, therefore it stands to reason that consuming the gland will add those hormones to one's body. There are also tablets made from dessicated bovine thyroid.
By the same reasoning, I have to assume dessicated BO is nothing more than a non-standardized source of estrogens. I'm too lazy to find out what other hormones the ovaries might produce. Given that synthetic estrogen pills or injections and bio-identical estrogens require either a T blocker or orchiectomy to be fully effective for feminization of genetic males and do not appear to cause this permanent aromatization effect that Transfemme claims for their product, I have to believe BO is nothing more than a weak and potentially inconsistent form of HRT and will still require some sort of AA to be fully effective. Furthermore, much like a genetic male taking pharmaceutical E, once the BO is stopped, the feminization will likely reverse to some degree, but sterility may be permanent as will any breast tissue growth, though the fat deposits in the breasts will shrink.
Then again, I could be totally wrong. Maybe BO is special, but I doubt it.