@Taxwolf
That’s the purpose of the Progress 8 score though: to reflect the level of improvement each school makes with the intake that they receive. Therefore it’s not just about final results, but the ‘value add’ that the school makes. HP scores significantly better by this measure also.
Like BDA, the HP catchment covers many large housing estates. I looked up the pupil premium figures for both schools - they are more or less the same with both around the 30% mark, (HPs is actually slightly higher) so HP by no means has a purely middle-class intake.
Regarding your point about admissions criteria, I believe that this change was because of a government directive from 2014, with the introduction of the Schools Admission Code. I think there are very very few schools in London that now work on a feeder school model. HP is in line with all the other secondary schools in the borough, where distance is one of the key criteria, which surely is how it should be? A state comprehensive should serve the local community, which makes distance the fairest model to implement. I think that perhaps as the school has become more successful, (meant in the literal sense of exam results - I know in other areas you would disagree), parents that might have looked at other options before are now opting in and so the distances are getting smaller.