I would have thought that, if what the judge said in the case where a child was placed in his father's care after his mother fell heavily into affirmation is any guide, the most appropriate place for a male child that is non gender conforming would be the scouts, where there is the opportunity to work with both boys and girls and the child does not close off the option of socialising as a boy.
Encouraging the GGs to change their policy is about society affirming the identity of transgender male to female persons, and is therefore the political act that the GGs were scornful of, and accused Fair Play for Women of, in their statement this morning.