I ran into an issue with all columns being required when creating/editing an ad code – notes are up on GitHub.

My current thought is to solve this by adding a filter to action_load_providers() that sets something like $optional_provider_columns that we can check alongside $ad_code[$slug] in create_ad_code() and edit_ad_code().

Does that sound reasonable? I can’t find anything that would break as a result of this change, but I’m still hunting.