Can one product have its own returns or warranty text, different from my store default?

Yes, if your store's returns Policy is turned on.

1. Open the product from Products → Products.
2. Find the Returns / Warranty summary card.
3. Write the text for this product, for example the warranty period and how to claim it.
4. Click Save.

This text appears on the product's Returns & Warranty tab on your store. Leave the card blank to show your store's default policy instead.

If you don't see the card, the returns Policy is not switched on in your Return Settings yet.