This learnt discussion is well above my head, but it convinced me to avoid Brooklyn on shabbos!
My question – given the subtlety of the issue and, in some cases, lack of clear psak – is it all 1/0? That is, if we have some allowing, others – not, would carrying be always considered hillul shabbos by those who do not allow, or it maybe something like “ok b’dieved” or “ok when going for a mitzva” or “ok when not observed by public”?