Make it easier and more practical to implement one-to-many fields

Marketo was built from the ground up on the idea that all fields should be on the person record.  Yes, you can pursue a one-to-many design using Custom Objects but they are difficult to use because they are implemented by way of API calls.

Features that could solve this:

• Add new "List Field" Fields Type that can hold multiple values.  
• Support one-to-many with Flow Steps to Add/Remove/Filter items in "List Field" or Custom Objects