[AliceDydro]

Additionally, you'll see the little caveat that synthetic progestin increases androgens.

There's an important distinction to make here. Synthetic progestins can have androgenic activity (they can bond with the androgen receptor) but they do not increase androgens (T/DHT). This is another orthodoxy that I see on transgender forums that leads to the nonsensical rejection of progesterone use by transwomen. From the study link:

MP [micronised progesterone] has been associated with a lower cardiovascular risk and has a neutral effect on blood pressure compared with [some] synthetic progestogens, which have androgenic activities.

Not all synthetic progestins bond with the androgen receptor, see the table on Wikipedia's article of Progestogens. There are at least 4 generations of progestins, so there is a wide variety of effects and risks.

Most HRT (if not all) medical professionals that treat HRT patients won't use progestin, they subscribe micronized progesterone.

Not for pro-growth effects, but they can use progestins like Spirolactone, Depo-Provera, and Androcur to lower Testosterone.

Interestingly, there are some reports that using Estrogen cream on the scrotum drastically reduces testosterone. I assume Progesterone cream would behave similarly.