I'm not quite sure what you mean by acceptable. Do you mean healthy? Or socially accepted? If I was doing something like that, I would probably verify with my OB that it wouldn't infringe on healing needs.
Personally, I encourage you to consider doing core workouts when you are cleared to exercise. Strengthening your core muscles will be a good way to ensure your body shifts back slowly and regains strength.
My hospital gave me a belly binder for post c-section recovery. You'll want to talk to your obgyn about what is best for you. I'm rarely wearing mine a week and a half later. It ended up bothering my back.
Re: Post pregnancy belly band... Is this acceptable?