No toes? Just stumps? How wide are his feet?
He won’t be able to hold on to a perch without toes...can you set up a platform perch for him to rest on? We have a macaw with a severe spine deformity that inhibits his freedom of movement and makes him more prone to falls. He goes down like a stone, doesn’t even try to flap. You can do a few things for him. If he will accept it, his perch can be lower in the cage, so if he falls he won’t fall far. You can put layers of corrugated cardboard around his cage in case of falls. Also, you can get these cheap interlocking closed cell foam floor pads. I’ve seen them for kids play spaces. For exercise...one of the members here, SilleIn, has a macaw that doesn’t fly because of an injury. She made a special harness to suspend him, and runs with him so that he flaps his wings.
Thanks for taking the poor baby in, and good luck!