There is absolutely nothing in Klingon society that indicates that they’d be accepting of trans individuals. There are a million things in Klingon society that, while not explicitly anti trans, heavily hint at a society that would not be accepting.
I feel like you like Star Trek and want every aspect of it to be explicitly pro trans. However instead of just acknowledging that Klingons were portrayed as extremely regressive anyway, you invent a headcanon and grasp as straws to justify it.