In relation to being transgender, I find satanism has given me an appreciation of myself as a trans man and other trans people that I never would have gotten elsewhere. In my beliefs, trans people are not just tolerated or accepted, but loved divinely and often rise to become great heroes.
Enki himself is said to have welcomed the first trans people warmly. (For those who don't know, Enki originated in ancient Sumer). In the myth "Enki and Ninmah," (
http://etcsl.orinst.ox.ac.uk/section1/tr112.htm) the gods are having a creativity contest. Ninmah, a goddess, is drunk and creates intersex and trans people. Enki welcomes the first trans and intersex people and gives them a spot on the kings council, and he even gives a trans man and a trans woman a job for Ishtar, one of the most holy goddesses in ancient Sumerian religion. How does that relate to satanism? Well, when the Abrahamic religions came around in the area, they began to call the Sumerian religions "satanic" and Ishtar herself morphed into the demon goddess Lilith. Some people believe Enki and Lucifer are the same being, but I believe they are different entities.
Baphomet, another being called Satan, is depicted here:

Baphomet represents balance; and so naturally, Baphomet is bigender and intersex. The rod with the snakes in Baphomet's lap represents the phallus and the breasts can clearly be seen.
As far as Lilith is concerned, I view her as a holy mother for satanists. She was said to give birth to hundreds of thousands of "demon children" (read the Alphabet of Ben Sira for more) and I believe that I'm one of her children that Yahweh couldn't kill. So naturally, she loves me as I am. I have no doubt she sees me as her son regardless of the fact that I am a trans man.
And Lucifer represents intelligence and knowledge. Why on earth would he dislike transness? I don't think he does.
So for me, satanism not only endorses transness, but celebrates it and regards it as holy.