Yes there is such a thing as lockdown. It is usually done the last 3 days before expected hatch time. I think 88% is maybe a little high for lockdown (boy, I sure don't have to type that very often!) I try to stay between 70-80% if I can. 75% is Ideal.
That said, lockdown for chickens is day 18. Lockdown for quial is day 14. Lockdown for turkeys is day 25 (and usually ducks too), but with waterfowl, especially geese, you've really got to watch the egg, candle at night, and put into lockdown when it pips internally. (You'll see a little pointy shadow moving around) If you candle every evening when your turning or checking your eggs, you'll realize that there is somthing else in the spot where there is usually no shadow. (you can search for pics, there are many posted on this sight back in March - June especially, or search the thread) Thats when you move waterfowl to lockdown.
Good Luck!