The shift size isn't going to affect pool hopping, PPLNS is still safe from pool hopping.
Making the shift size extremely small I think would be a bad idea. It would scare the ones that are shocked to see a shift with zero pay. I have to balance between that and the people who think if 10 shifts take 5 days it means they have to mine 5 days with lousy pay before proper pay starts. So I try to keep it somewhere in the middle.
To be honest? That is exactly what I thought... It is what as been keeping me from bringing more gear online on this pool. At this rate, I'd use up half a difficulty level bringing up my "share per shift" and I just can't afford it. In my other pool I'm being paid per share and if I add more I get paid more.
Where can I read how this actually works?