I suspect it's like any other field.
Let your political extremist lobby with no conscience, no safeguarding training of any kind, no training at all or interest in equality or impact on any other group save the useful one, a strong personal agenda and a difficult relationship with facts enter school freely.
Let them teach staff their own version of the law, not mentioning that they've re written it to say what they want it to say. Make a lot of emotive and scary noises about the extreme vulnerabilities and dangers and the risks of being sued.
Heavily weight the dice with that nice and good people think and do this, and nasty old fashioned bigots think that, and make sure they know what's acceptable and what's not, and that it's going to be socially and possibly quite actually dangerous to careers and livelihoods to not be in their gang.
Then let the lobby kindly offer to write policies for busy people because they are the experts, and let those busy and naively trusting schools think they're being helped in going straight to the right, objective answers by the objective experts in the field. Usually without checking for example the social media feed of the trainer. Or checking their actual qualifications.
Then let the lobby throw a lot of stuff into social media and online making it clear that anyone with doubts or saying anything other than this is a nasty, old, ugly, frigid, extreme right wing bigot who shags Trump and eats kittens and goes to Tescos wearing headscarves and Jackboots. And encourage and support the disposal of anyone who dares say anything.
Bake for about eight years. Sit back and enjoy your political capture safeguarding disaster on toast. Many of the captured will be well intentioned people. Who have been fed limited, careful information and taught to reject anything but that information. I'm not exaggerating when I say that Prevent may need eventually to help and advise on undoing this.