Regarding PPLNS:
interessting system. but it would just change hopping styles:
as i get it, u now join fresh rounds and leave when they take to long, and come back if a new one starts.
with pplns it's just the opposite. u join the long rounds, because they should be over soon and hopefully followed by shorter rounds, so u get paid triple and more. then leaving at the beginning of a new round in fear of a long round, where the first shares aren't worth anything. and being worth nothing should be a even stronger driving factor than being worth less.
I have no doubt that some people would think this way, but it offers no benefit to the hopper nor damage to the pool.
There is no such thing as 'this pool is due'. There is no way to tell, based on history, that a pool is going to hit more than average blocks soon. So there's no way to determine now is a better or worse time than average for participation in PPLNS.
To the extent people believe the 'something's-due' fallacy, it could be self-limiting. Superstitious people may pile into a pool that seems to have gone a long wall-clock-time without a block. Now larger, the pool will tend to hit a block in less wall-clock-time. Of course it takes just as long in share-tick-time, and gets divided over more separate contributors in the last-N window, so the acceleration is exactly offset by reduction in payout. Neither hopper nor veteran gains or loses expectation from the piling in.
But, they all gain from the lower variance, as more trials in the same wall-clock-time means better convergence to PPS-like payouts. So to the extent subscribers to the gambler's fallacy do jump in after unlucky periods, they reduce variance just at those times when it becomes embarrassing to the pool. A simple graph that obscured hashrate changes over time might make such a pool look unnaturally lucky.