The white stuff isn't trenbolone acetate, so if anything it's an advantage when it doesn't go through the skin.
I can't say for sure on the microwaving. I never did do any work or study in the area of microwaves and chemical reactions. Some strange things can happen and I don't know how to predict them.
Anecdotally, one of the supplement products I came up with, a novel compound, worked great for me, but when I sent it off for other subjects to test, it was a complete dud. I mean absolute failure: worthless. It seemed very strange, because I was really sure of it. Turned out it was microwaving. I didn't use the microwave in preparing the samples for my own use, but for some reason I did so for the batch that was sent out. Later it proved consistently that microwaving de-activated the compound.
So although I don't understand when it happens and can't predict it, I have seen it happen.
I also recall a study in The Lancet back in the 80's... researchers found that some compound, I've long since forgotten which, in infant formula is largely changed to a different isomer when the formula is microwaved, and the altered compound was found to be taken up into the brain and incorporated there. Alarming. So, a second example of that kind of thing.
Relevant to trenbolone? I don't know.