I think when a sub says "you can do whatever you want to me" what they're actually wanting is to not make decisions anymore, and they think by saying this they can foist the decision making off on the dom without having to do any of the work beforehand. But unfortunately to get to the Not Making Choices part of kink you do in fact have to make a Lot Of Choices beforehand and communicate those choices to your partner. This is an essential part of the process and skipping it is both unsafe and unfair for whoever you're playing with.

the thing about transfem supremacy is that it is a bioessentialist kink, and you have to acknowledge this and understand what you’re doing. it’s not, like… real. I enjoy bioessentialism kink for myself as a sub, which is why it’s incredibly hot to me when transfems like to dom that way– but I think if you’re tme you need to be incredibly careful about how you engage with tfem supremacy content and watch out that those fantasies don’t become flat-out beliefs. transfems are not actually more sexually aggressive or even more inclined towards topping/domming than cis women