Has there been any update in the API for custom named custom fields?
We would like to have custom names to help keep from confusion happening.
Additionally, when using custom fields in the emails we have seen that the values sometimes do not show up when we use Custom_Field_#. This is part of the reason we want to use specific names for te custom fields.
Currently it is still only possible to use the custom fields that are named "Custom Field 1-15". One possibility for the difficulty you've had with values not appearing is that you may have multiple fields in your account with similar names(this is more likely if some fields were created in the UI). You can find information for managing custom fields here: https://knowledgebase.constantcontact.com/articles/KnowledgeBase/5328-add-and-manage-custom-fields
If you do not have any similarly named fields that could be responsible for information not showing up, please let me know and I'll be happy to help you dig deeper!