I've learned that, yes you can return an engraved Apple products back to Apple within 14 days of purchase date.

Are engraved AirPods returnable?

Apple is now allowing users to customize their AirPods and AirPods Pro case with a single emoji engraving. ... Engraving a product may take longer to ship to users, and any engraved device cannot be returned for a refund.

Can I return iPad after engraving?

If the gift you received has been personalised, such as an engraved iPad, then you won't be able to return it as the device will be unsellable to another customer.