Feminists who have my respect dont deply such tactics.
I'm not sure if you're being disingenuous, or you genuinely don't understand why people question your assertion that no one knows you're trans.
The reason people question it, is because asserting that transwomen are in women's spaces and no one knows is a position that needs challenging.
Women are reluctant to challenge male individuals in person, because experience tells them it's a risky tactic. Or they may be being kind.
There are 6,500 genetic differences between men and women and women are socialised almost as soon as they are aware, to spot them.
It's not spite! It's in response to your assertion that no one knows. Because if women genuinely don't know, aside from the question of potential deceit, they shouldn't be making any kind of objection. Therefore it is refuted. It's not because women are being 'vile'.