[mothered]

Yeezys only have a 7 day return policy after being returned and today is the last day to return. Should I drop the EB attempt, and just try the boxing method with some dry ice or something like that.

If you're concerned about the return policy expiring, you've got nothing to gain by switching methods - boxing them will (most likely) also trigger an Investigation.

The weight of the package that came was listed at 3.00 lbs or 1.361kg

That's the gross/shipping weight, which Is Immaterial to your claim.

What's the precise weight of the Yeezys?