Check out the past threads on Mumsnet about this - the concern has always been for the females in such scenarios, ie. the females being searched and the females enacting the searches as part of their duties.
FWR can absolutely be critical of police responses and policies, especially when the actions are targeted against women and by transgender offenders appear to be given preferential treatment (ie TRAs given a free pass despite being violent, obscene and threatening, whereas women being interviewed/warned, arrested and charged for ribbons, stickers and being “untoward about paedophiles). This doesn’t change the concern we have for women being placed in a position where they have to search a biological male who insists they are a woman.