I would only leave the chick in there for a few hours at a time. They can struggle to get out, and can get hurt, so keep an eye on them. Place food and water close enough to reach. Here are a bunch of homemade chairs and slings:
A friend built this for my girls. Cathy fell off a truck on its way to the processing plant and broke her pelvis over a year ago, and she gets scrapes on her legs sometimes, so this helps get the pressure off.
This has to be the first thing I’ve ever seen. I’m wondering how they turn out if you use this when young? I’m also wondering how long per day they stay in it? Only when you let the others run around free range? I wonder because I have a gimpy turkey that steps on his own feet from splay leg when he was a little two week old poult I think. He’s had problems from the start and they’re pets so I cannot bear to cull him.
Some birds will tolerate a chicken sling or chair, while others will try to climb out of them, and can injure themselves. They are for using for shot periods of time, and they need to get out of them periodically to stretch or sleep, or for physical therapy or exercise. Hopefully they are for temporary use, but they can get a chicken ip and out of their droppings. Food and water can be placed in front of them within reach. I think you would would want to supervise being together with other flock members to determine if it is safe to be left in the sling.