My client has a wholesale section on his site, which only pre-approved (logged-in) users can access. I am utilizing the client's CMS for the creation of users and syncing the information with Foxycart via SSO and the API.
The above is working just fine, but I am having trouble grasping how best to pre-populate the address information for these users on checkout.
According to the docs, I should not use the customer pre-population fields. However, the customer_address_save method from the API only works with multi-ship.
Is there a different method I should be using?