I get the feeling that those studies/surveys you speak of included another form of progestogen as bio-identical progesterone does not increase cardiovascular risk and actually exerts an ANTI-DEPRESSIVE effect due to allopregnanolone.
There are several studies that I can share that show that progesterone helps with breast maturation and growth while cardiovascular complications aren't observed.
Here are just a few:
* J Womens Health Gend Based Med. 2000 May;9(4):381-7
"When compared with the MPA-containing
regimen, women using micronized progesterone-containing HRT
experienced significant improvement in vasomotor symptoms, somatic
complaints, and anxiety and depressive symptoms."
* Menopause. 2002 Jul-Aug;9(4):253-63.
"In contrast with the widely held belief among psychiatrists that progesterone depresses mood, neither of the progestogens we used in normal, nondepressed and nonanxious women showed this effect. Absence of an effect on mood was also found when the results of the two progestogens were combined. The lesser side effects of the micronized progesterone-containing regimen suggest that some women may prefer it to an MPA-containing regimen."
* Trends in Endocrinology & Metabolism
Volume 11, Issue 2, 1 March 2000, Pages 69–71
"Curiously, addition of the synthetic progestin, medroxyprogesterone, blocked the modulating effects of oestrogen on serotonin activity, while natural progesterone did not."
* Steroids. 2004 Mar;69(3):145-59.
"(...) The importance of the sex steroid hormones 17beta-estradiol
and progesterone for normal development of the mammary gland was
recognized several decades ago and has been unequivocally confirmed
since."
* Am J Surg Pathol. 2000 Jan;24(1):74-80.
"(...) Hence, combined progestative antiandrogens and estrogens are
necessary for genetically male breast tissue to mimic the natural
histology of the female breast."
"Our findings in patient F indicate that prolonged and
regular intake of proper doses of progestins and estrogens
is needed for the full development and maintenance
of the female histology."
"(...)progestative drugs are known to stimulate
the formation of acini and lobules in females.7 "
* Climacteric. 2013 Aug;16 Suppl 1:69-78
"Once a pregnancy occurs, progesterone
is necessary for the full differentiation of breast tissue that
occurs in preparation for lactation. In the mammary gland,
progesterone acts synergistically with estrogen to transform
the terminal end buds into differentiated lobules necessary for
milk secretion 4."
* Volume 18a of Elsevier's New Comprehensive
Biochemistry, Titled 'Hormones and Their Actions, Part I'
"Progesterone also acts synergistically with estrogen in the normal
development of the breast. Estrogen stimulates cell mitosis and growth
of the ductal system, while lobular development and differentiation is
dependent on progesterone. When estrogen is administered in the absence
of progesterone, the tubular system proliferates and the ducts dilate
resulting in the formation of cysts and fibroses. These changes are
comparable to those observed in fibrocystic disease and are suppressed
by progestins, so that normal breast development requires that estrogen
and progesterone be administered together.[2-4]"
* Experimental and Clinical Psychopharmacology
2007, Vol. 15, No. 5, 427–444
"Progesterone has been shown to be safe and effective for many clinical applications. The therapeutic effects of progesterone and its neuroactive metabolites reflect interactions with serotonin, dopamine, Nmethyl- D-aspartate, beta-endorphin, and sigma receptors (Pluchino et al., 2006; Schumacher et al., 2007)."
* Contraception. 1987 Oct;36(4):373-402.
"No side effects have been reported as far as lipids profile, coagulation factors and blood pressure are concerned. Therefore oral micronized progesterone appears suitable for hormonal replacement therapy in various areas, essentially postmenopause therapy, premenstrual syndrome, correction of irregular cycles and pregnancy maintenance."
* Climacteric. 2012 Apr;15 Suppl 1:11-7.
"Micronized progesterone has also been shown not to increase the risk of venous thromboembolism and further reduced the incidence of new-onset diabetes when combined with transdermal estrogen. Micronized progesterone has a neutral effect on the vasculature, including a neutral or beneficial effect on blood pressure"
* Menopause. 2010 Nov-Dec;17(6):1122-7.
"there was no significant change in APC sensitivity among women who used transdermal estrogens combined with micronized progesterone compared with nonusers."
* Menopause. 2014 Jan 6.
"Results of this small, double-blind, placebo-controlled, cross-over study showed that the use of orally administered natural progesterone caused a significant reduction in BP in individuals with mild to moderate HTN who were not using any other antihypertensive medications"
* Lipids Health Dis. 2012 Oct 9;11:133.
"The effects of intranasal and percutaneous estradiol were similar, regardless of the addition of progesterone. Similarly, for the overall group of 86 women, micronized progesterone did not alter the response to E2. Blood pressure, glucose, insulin, HDL-c, triglycerides, and usCRP remained constant with or without micronized progesterone. Total cholesterol decreased after E2, and progesterone maintained this reduction. LDL-c levels were similar at baseline and with E2, and lower during E2+P in relation to baseline."
"Cyclic, short term exposure to vaginal micronized progesterone did not alter the metabolic and cardiovascular effects of non-oral E2 in early, apparently healthy, postmenopausal women."
* Hum Reprod. 1999 Mar;14(3):606-10.
"Natural progesterone is devoid of any androgenic activity that might compromise lipoprotein metabolism or induce teratogenicity. Moreover, it probably has a direct beneficial effect on blood vessels."
* J Hypertens. 2003 Jun;21(6):1145-9.
"We conclude that progesterone given without oestrogen does not adversely affect vascular function in postmenopausal women."
* PLoS One. 2014 Jan 21;9(1)
"Results indicate that progesterone has short-term cardiovascular safety. Endothelial function, weight, blood pressure, waist circumference, inflammation and coagulation were unchanged as were lipids except for HDL-C. The statistically significant decrease in HDL-C levels was not clinically important (based on lack of Cardiovascular Risk Profile change)."
* CLINICAL THERAPEUTIC VOL. 21, NO. 1, 1999
"the most commonly used synthetic progestins, norethisterone and medroxyprogesterone acetate, have been associated with metabolic and vascular side effects (eg, suppression of the vasodilating effect of estrogens) in both experimental and human controlled studies.All comparative studies to date conclude that the side effects of synthetic progestins can be minimized or eliminated through the use of natural progesterone, which is identical to the steroid produced by the corpus luteum."
"Several studies, including the 3-year prospective PEP1 study, 4, 28 have shown that oral micronized progesterone significantly improves metabolic tolerance compared with such progestins as MPA.52,54,58"
* Med Hypotheses. 2001 Feb;56(2):213-6.
"Oral replacement therapy featuring micronized
progesterone, if administered throughout postmenopausal life, can be
expected to have a highly positive impact on vascular health"
* Climacteric. 2003 Dec;6(4):293-301.
"In both peripheral and cerebral vasculature,
synthetic progestins caused endothelial disruption, accumulation of
monocytes in the vessel wall, platelet activation and clot
formation, which are early events in atherosclerosis, inflammation
and thrombosis. Natural progesterone or estrogens did not show such
toxicity."
* Climacteric. 2013 Aug;16 Suppl 1:44-53.
"Natural, 'body-identical' progesterone, devoid of any androgenic as well as glucocorticoid activities but being slightly hypotensive due to its antimineralocorticoid activity, appears to be the optimal progestogen in terms of cardiovascular effects, blood pressure, VTE, probably stroke and even breast cancer."
* Experimental and Clinical Psychopharmacology 2007, Vol. 15, No. 5, 427–444
"It is important to note that although progesterone and synthetic progestins are used for similar purposes, these may not exert similar modulatory effects on target organs, and each progestin molecule may have specific effects on neuroendocrine action (Bernardi et al., 2006). For example, a commonly used progestin, MPA, was shown to induce more negative somatic effects, more reports of breast tenderness, and increased magnitude and duration of vaginal bleeding in comparison with natural (micronized, oil-suspended) progesterone in early menopausal women (Cummings & Brizendine, 2002). MPA and natural progesterone also were found to differ with respect to molecular signaling in human endothelial cells, suggesting that there may be differential cardiovascular effects (Simoncini et al., 2004)."
* Climacteric. 2013 Aug;16 Suppl 1:69-78.
"Estradiol has been shown to trigger the expression of the
endothelial nitric oxide synthase (eNOS) gene and increase the
release of nitric oxide, causing relaxation of the vascular
smooth muscle cells. "
"Progesterone or drospirenone did not interfere with the induction or activation
of eNOS by estradiol, while MPA did."
* Biol Psychol. 2005 Apr;69(1):39-56.
"Women assigned to Estratab plus Prometrium had diminished diastolic blood pressure responses during a speech stressor upon retesting, whereas women assigned to Estratab plus Provera increased."
* Steroids. 2003 Nov;68(10-13):831-6.
"These data have been confirmed by other groups, showing that progesterone plus estradiol protects, but MPA plus estradiol does not, against coronary artery vasospasm[19], thus highlighting the difference between natural progesterone and MPA."
"Recent work looking at the additional effects of natural progesterone or MPA on coronary blood flow and myocardial ischemia in postmenopausal women shows that progesterone has synergistic vasodilatory effects when added to estrogens [26]. In contrast, MPA does not share this action, therefore indicating that, on this particular target, all progestins are not the same [26]."
By the way, progesterone levels skyrocket during pregnancy. Are pregnant women dying left and right or having heart attacks?
And this last study
* Climacteric. 2013 Aug;16 Suppl 1:69-78.
"none of the recent statements addressed the
difference between MPA and progesterone, even though the
differences in action between the two molecules have been
demonstrated in receptor interaction and transactivation 1,16
and in vivo , in vessels 79 , brain 80 , and heart 81 . It would be
unfortunate if this confusion between the molecules deprives
menopausal women of the well-known effects and benefits of
progesterone."
I think it is critical for all those following HRT to understand the differences between progestogens (and estrogens/anti-androgens) and rely on science rather than hearsay to sort out what is fact from what is myth. Armed with this knowledge, one is better able to oversee their treatment in collaboration with a competent doctor who can, sometimes, learn from us. This can become a beautiful partnership between patient and doctor. 
This is the reason I cite all these studies. To help the transgender community and those treating them.
