Help with magpie duck eggs

[pteroo]

Hello, new hatcher here! I'm having trouble finding in-depth information on Magpie duck egg incubation anywhere online I currently have 2 eggs left (1 infertile) in my Brinsea mini II Eco incubator on around day 19/20. They've been developing nicely so far, lots of movement and veins. I'm not sure of their air cell though, which is looking a weird shape? Although I can't seem to find any solid info on their incubation period (everything is contradicting, I've read that they hatch quicker, 20 days, but others say they take just as long as other ducks 25-30 days), so I don't know if it's dipping and their due to internally pip soon? If anyone can shed some light on this and magpie duck incubation in general, I would be very grateful! I've also added some pics/videos of them from last night.

(Re-posting in this specific duck forum)

 

[Percipen]

They take 28 days to incubate like any other mallard derived breed. So, on day 26 they can go into lockdown and by day 28 you should have some new babies. I've had a couple odd air sacs like that and never had any issues with hatches because of them.