[Green314]

Use caution if using sealed box method in person, especially with apple products, and even more so if paying with cash/getting a cash refund (for anonymity purposes). I highly recommend undertaking a dry run first

Just from personal experience

I would imagine if you were to seal an Apple product with the wrapping and it looks just like the real one they would not open it up and check it. It would seem as if you have not even opened the box before returning.
My thinking is that they would want to sell it as new, and if it appears to be new they wouldn't want to devalue the product. Maybe my train of thought is wrong so please share more.

If I were Apple, I would check each return.
Even if they are sealed, I would unwrap them and wrap them again. I don't think they have to do use plastic envelopes frugally.

And I think they do it. The feeling of receiving a different item, than what you paid for (so much money) would give to the customer an enormous bad image of the company. Apple can't afford this.