Many peafowl people think that splay legs and/or curled toes can be attributed to them being in the shell too long and/or too high humidity. Of course shipped eggs have their own set of problems, too.
Not suggesting that you make any changes, just sharing what I have read.
Would that be high humidity during the first 18, or at lockdown?
I usually run a dry hatch. My humidity during my first 7 or so hatches was around 37, but lately it's been in the low 20s. I have been adding a small damp sponge to bump it up to the 30's.
Lockdown, I run 65-75. But at night, I bump it higher, since it's drops to the 50's if I don't. So, for part of the night it's up it he high 80's. Is it better to let it drop for a few hours, or bump it too high for a few?
It's funny, the problem chickens have mostly been first born. The one I had to cull was the one I had to assist out of the shell. Because of that I will probably never assist again, If they are not strong enough to hatch, they probably won't be strong enough to survive. If they do hatch and have trouble, and I can help, I will.