[mothered]

But what's the harm in returning the empty box? Just the lower resell value?

They probably need It to bring It to the attention of the manufacturer.

I'd found that as well, why do airpods/apple watches have a higher success rate than CPUs/other EB items? Is it just the lower weight?

Predominantly due to the lower weight.

Even 15-20 grams less can make a difference In a successful outcome.

The GPU is not shrink-wrapped in plastic if that's what you mean. The only type of seals I can see are on the outer box and the adhesive on the anti-static bag within the box which holds the GPU.

If It contains factory seals that requires to take them apart to open the box, then the sealed box method can be used.

Of course, the box must be fully covered In cardboard.