tbh even if that was legitimate evidence, (and to be clear let me repeat IT IS NOT).
The idea that it would be required even if female officers consent just does not follow. It just makes no sense.
In the High Court today for a challenge by Sex Matters to police strip search guidance. They say even if female officers consent, strip searches of trans women have to be done by male officers.
Part of their submitted evidence is a "table of trans-identifying males who have committed sex crimes".