[Waifu]

Though, I don't think many high weighted items need a signature when delivered.

As per my example above and In terms of purely SEing companies for refunds/replacements, the weight has very little relevance when deeming whether a signature Is warranted.

From a social engineering standpoint, DNAs are solely based on manipulating receipt of goods.

Totally agree with the comment you made above about the diamond. Although DNAs have been used for years now, it still has an extremely high possibility to manipulate the receipt of goods (as you stated) .