I added a photo that shows the pop door which does utilize a ramp so you think they will get stuck outside potentially?
I do have rest boxes ground level so they could bunker in there I can have food/water on coop floor but like you said it will likely get buried in shaving and/or knocked over...
I just had my first broody hen successfully hatch 4 chicks. They are in a sequestered pen in the coop with their own food and water. All the flock can see them through the chicken wire.
How long should she stay in there with the chicks?
Im pretty confident she will protect them from the other...