One of my clients has switched to DPD because this feature is missing, and others are considering moving away from C&D too. Entering/syncing HS codes, customs descriptions and country of origin information manually is not a viable solution when you have a fast-changing product catalogue.

There is no reason not to support it as the Shopify API exposes this info both when retrieving product data and order data. For example, in the GraphQL API:

Order.lineItems[].variant.inventoryItem.[ countryCodeOfOrigin | harmonizedSystemCode ]
Product.variants[].inventoryItem.[ countryCodeOfOrigin | harmonizedSystemCode ]

In Oct. 2022 - We are a new (potential) customer testing C&D.
We told C&D Support that our Customs data (HSCodes etc.) were not being imported from Shopify. They asked for evidence, we supplied it ... and waited for a response/solution/work-around/anything!!
Then I found this post - And see it was DECLINED in July!!

So it's never worked! Why then ask for evidence??
And why decline the suggestion because "it's not possible at the moment" ??
That's the reason for a 'suggestion'!

What a waste of our time!
It has the possibility to be a great product, but not managed like this!

Having these mapped to the customs code along with the country of origin, would be fantastic. I currently have to copy and paste over from Shopify where I've entered them for all my products.

Many thanks for your message.
All HS codes are sitting on Shopify, I'm sure data access feed shouldn't be a problem.
Thinking more about Northern Ireland (NI) in October 2021 when HS codes seems to be required.

Reason for enquiry is that we received the following email from RM indicating that our electronic customs data is not compliant.

To support you in this process we have been monitoring your customs data, to identify areas of non-compliance. Please see details of the fields that you are not consistently completing below. In order to be fully compliant you need to resolve the following issues:

Unit Weight
Unit Value
Country Of Origin
Trade Tariff
Quantity Of Units
Unit Description
Postage Cost
Sender Country