Another idea I had to put them on the ground to forage yet small enough to move about the garden and yard. I made this with an addtional smaller base but then decided they needed to have some romp-around space. I think this would be good for coturnix. I'm always building and comin up with something new.
snakes are issues down here. maybe hardware cloth on the bottom?
I like your design. Is the quail smart enough to laying egg and get to roost in the coop at night? If not, you may end up craw inside to collect egg every day which is not fun.