What I keep telling hw companies - you NEED quality control.
Many products will also have inconsistent weight, not only between units (not everything is made to NASA specs, and anything handmade or harvested will have huge variations) but also after shipping (labels on box, seal tape or cellophane removed, cardboard absorbing moisture, …).
QC before restocking is fine. On the shipping side you just check that it’s the right product and that the packaging is intact and not indicative of damage.
Someone returned one of their diapers used. They trusted Amazon to handle returns and labeling of inventory. Amazon labeled the used diaper as "new," and consumers assumed the diaper company was responsible for the mixup.
This is an issue with Amazon's handling of returns, which is exacerbated by their inventory mixing (all items of the same SKU are considered "the same" and interchangeable, regardless of their provenance).