I decided to cut mine because I couldn't wait any longer to see what I had. (It's my first clutch and I am impatient)
I did so on day 55 and 2 days later they are all still in their eggs under the sack thing.
I've been opening the lids to let air in about twice a day and trying to leave them alone as much as possible so they come out but nothing yet.

I have checked and they are all still alive and moving so hopefully they'll come out soon.

They have all very distinctive black pattern but none of them look like normals. I can't imagine they'd still be developing pigment at this late so I may very well have a full clutch of pastels. All 7 babies look the same with no brown that I can see.