If you use the impression kit and it turns out that you aren’t suited to NewSmile treatment, then you will be refunded in full – there’s no obligation to pay for a treatment that you aren’t suited for. However, if you are suitable but you change your mind, you won’t be able to get a refund.
NewSmile will already have started funding your custom-made aligners, and they can’t just be reused for someone else. Every smile is different. So make sure you’re committed to going through with the treatment before you buy.