Should I map the whole Hotel-X Destination List?

The answer will depend on your interests.

Connecting with a new Seller not always mean that you are interested in the whole portfolio, maybe you are just interested in the properties located in a few specific destinations. It's in those cases where you can map only the destinations you are interested.

For instance, lets imagine that you are interested only in the Spanish inventory of a given Seller. In that case, you can filter the Destination List query adding the "destinationCodes" field to your criteria and setting it to "ES" (country codes will always be in ISO 3166-1 aplpha-2):

*More information on our Playground in the DOCS tab.

In the response  you will receive all the destinations that hang from the "ES" zone: