[mothered]

On the 20th June 2020 I received the “Refund” email which says I’ve done a high number of refunds. Since then I’ve placed like 4-5 legit orders. Is it safe for me to do the sealed box method

Yes It Is safe to go ahead with the method.

You've allowed ample time, as well as built some credibility on the account with legit orders.

Do I have to carefully reseal the iPhone box or the Amazon delivery box?

There's a couple of options:

1. You can claim that the Amazon box was opened, but then changed your mind with the IPhone, hence return the phone In Its original untouched condition.

2.  To play It safe and give the SE a better chance of success, reseal both the Amazon & IPhone box to perfection, thus return the entire consignment (seemingly) without touching It. This gives them less of a reason to check the return.