A) Lowering estradiol or its effects at the receptor site too much and there are detrimental side effects as stated. In fact low estradiol and low testosterone feel very similar symptomatically.
This is not just my anecdotal feeling but the feelings of many, many hypogonadal men who have had issues relating to the balancing of hormones. The side effects I have stated are also detailed in many medical journals.
B)
Soy is of debatable interest, some hormone specialists think it is largely irrelevant, some see it as a weak SERM and others see it as a hazard. In all honesty I disregard it entirely. I think for someone with fairly well balanced hormones and little glandular gynecomastia like yourself that it is irrelevant IMHO, though I am sure people will pull up half baked studies stating otherwise.
C)
A rebound effect is due to a "significant" shift in the endocrine balance in favor of estrogens, with significant being the operative word.
This rebound effect is seen in men abusing anabolic steroids. In such cases they have very high supraphysilogical levels of testosterone which in turn results in supraphisilogical levels of one of its main metabolites- estradiol. With very high testosterone levels estradiol is not able to act unopposed (ordinarily/excluding poor genetics, liver conditions, other hormonal factors etc) in the endocrine system and much like a tug-of-war where each side is of equal strength homeostasis (balance) is maintained and estrogen related side effects such as gynecomastia are usually not seen.
As soon as the steroid cycle is stopped such men find that their testosterone levels plummet. While they have been abusing steroids their Hypothalamu/pituitary has recognized the excess testosterone and shutdown all production of LH/its own testosterone production and now without the external supply of testosterone they have to wait whilst their own hypothalamus/pituitary re-starts. During this time estradiol is able to act unopposed and by a cruel qwerk of fate estradiol unlike testosterone takes a long time to return to normal levels and in fact hinders the hypothalamus/pituitary from kick-starting LH and testosterone production. Think of that tug of war with two sides of equal strength, think of what happens if one side lets go of the rope. If you don’t like the rope analogy, think of what happens on a set of scales when two items opposing each other are of equal weight and one is removed. Both analogies are exactly the same, in both instances the forces of one side are able to act unopposed and unopposed estradiol causes gynecomastia.
There are many other ways this rebound effect can occur but they should not relate to your situation.
D)
In your situation unless your estradiol was VERY high prior to treatment or is VERY high now then a significant and adverse shift shouldn’t occur with treatment removal and certainly you do not have testicular shutdown judging by your LH and testosterone levels. Couple this once again with the fact that you have little glandular mass and the fact that your gynecomastia is idiopathic (I recall you telling me that no cause for it was found) and most likely a temporary pubertal imbalance that no longer exists;
It all points to a situation where you wouldn’t really expect any issue with treatment removal.
Endocrine medicated intervention is about creating an ultra positive endocrine balance for a short period of time to try and resolve glandular gynecomastia and then taking away the powerful medications and returning to a normal endocrine balance (clearing up the after effects of pubertal imbalances).
E)
Tapering down Tamoxifen and stacking various drugs are things that bodybuilders are obsessed with and an quite honestly some of the time these factors are irrelevant and the individuals do not understand the mechanisms at play.
As it stands every man and his dog reads crap on bodybuilding sites and gets hold of these terms and applies them to everything from creatine to Milk Thistle. Everyone of these guys is an expert, but virtually none of them understand or get pathology and many of them end up here.
D)
You’re overanalyzing everything
It sounds very simple, but if you feel well and have no symptoms of ill health it is usually safe to say that you are in fact well and this is backed up by the fact that nothing has been found via endocrine investigations
If there is no evidence to say you are ill in any way, try and deal with the gynecomastia either via the prescribed course of medication or via surgery and then just get on with life.
If you are finding that difficult and still feel the need to over analyse the minutiae of your own health then you might need to see a therapist to talk through your concerns/issues and rule out BDD (which is as significant as condition as gynecomastia in its own right- and not to be underestimated).