Can we let the chickens go under this or will they hurt themselves?

So first time with chickens, soon to go to their coop. This is it (we have to finish the inside, hardware cloth over windows and soffit vents, and build the run).

My question: I know they like going under things, and would like to enclose/predator proof the underside of the coop and have it be connected to the run. At the lowest point the coop is about 4" from the ground. Highest about 16". Will they somehow get stuck/hurt themselves at the low point if we leave this open for them, or will it be okay?

What would y'all do?

(Edited to add that we'll be adding hardware cloth to windows.)