Duck eggs w/ weird air sacs! Please help!

[Kiwiduck34]

Hello!
I’ve currently got 8 mallard duck eggs incubating in my homemade incubator with an automatic turner. My temp has been averaging at 99-100° and humidity has been around 50-55%. My problem is that 6 of the eggs look like they have smaller than usual air sacs and two of them have huge air sacs. Plus, one of the ones that has a huge air sac also looks like it has fluid in the air sac. (I plan on hatching this one in an egg carton) They are currently on day 20 of incubation. I candled them today and they are all moving about. I've been misting them once a day since day 15. I’ve hatched ducks out before but I’ve only had one with an unusually large air sac and it hatched out just fine. I do have another incubator at my disposal if I need to split them up. Should I leave the 6 in the incubator, lower the humidity, and keep misting them daily? Meanwhile I could move the two odd ones to another incubator with 55% humidity and not mist them at all.
Does anyone have any advice on what to do? Thanks!

 

[AquaDuck]

Do you know if the eggs with the big air cells are older than the others? That could explain the difference, as air cells grow increasingly larger the older the eggs are. Another reason could be that they're further along the development and will be hatching earlier than the rest.
In any case, if it's easy for you to set up the 2nd incubator, I'd do that. Only a week left of incubation and they clearly need different treatment. If they do hatch earlier it'll be easier to deal with too.

 

[Kiwiduck34]

All the eggs arrived at the same time. I ordered them And they came in the mail.

 

[Kiwiduck34]

Okay I put the two unusual ones in a different incubator. Does anyone have any tips for hatching an egg that has fluid in the air sac?