really?? to be honest, i don't think there will be any difference unless you don't need to attend the interview again next year
it's because, some many people will apply k1 (included big b) who didn't apply the pn / rejected when they applied for pn ... and also the admin is quite messy and i really don't think they will mark down in the application form (just my personal opinion);
so, for small b, i think it's better to apply pn next year, as hkps will start writing in k1 which is difficult for small kids, and also the chance to get a place is much much higher