I realize that it only happens once every 2 years.
Or perhaps once every 4 years?
With a pay per last N shares system, there is a discontinuity when the minting fee changes.
If you submit a share for a 25 BTC block from just before the change, you are paid out by a 12.5BTC block.
To keep it fair, shares after the discontinuity should be worth half as much as before. The has the effect of doubling N.
This means that a pool where N is 3 blocks would need to change its N to 6 blocks after the change.
Do pools do stuff like that, or is the effect mostly ignored? It only covers a window of a few hours/days, so is probably not that big a deal.
Whatever the answer is today would be useless, since the pools could change the rules before the next adjustment (nearly 3 years from now).