The app is giving me a green tick and I have the answer for 13 down which most posters have, ie not Barbados. Did anyone else toy with the Pauline 'shagtastic' for 24 across until ruled out by crossers? Not a word in my vocabulary but it popped in the solver.
With regard to 13d presumably the London location is required but there are three others with partners changed in Australia, Barbados (as mentioned in an earlier post) and New Zealand so it would seem that answers with either partner as letter 4 are correct.