As I quoted later, PoolWaffle later provided updates as to the severity of the issue. "Jacked up miners" were less significant then originally considered.
PoolWaffle also published a chart a long time ago that showed graphed miner's switching times. Let me dig it up and provide some proper background on this, if you insist.
The "jacked up miners" thing is debunked, as far as I am concerned. The new scheme now serves mainly to (statistically) penalize shares for fast switching coins and creates imbalance on a profit switching pool that mines multiple coins at once.
These 'reject' rates should be tracked internally, sure, but they are of main relevance to the coin switcher - not the miners. This seems an ideal way to balance portions of a switching pool into segments - your fast switching miners could be thrown around to different coins, and maybe even receive a small bonus (1-2%?) for this. The slower switching miners tuned for a longer block coin can mine litecoin or another higher diff coin.
This is roughly correct, and a decent bit of the reason the new switcher assigns rotating sections of the pool. Having a 10% reject rate on a certain coin is worth it if that coin is 11% more profitable overall, however, during that time obviously the miner getting the 10% reject rate is at a slight disadvantage, as long as that slight disadvantage rotates around the pool evenly, everything works out fine. I haven't seen anything yet to raise suspicion that users are abusing this, but it wouldn't be tough to either credit the X% over average stalerate that a faster coin should yield, or to detect it to begin with. Due to the short amount of time we actually mine coins that have fast block times to begin with, trying to abuse it is probably not very effective anyway, but I'll definitely start adding some monitoring for it and see if anything comes up.