Hi Kelly,
You’re correct, the screen used for building the list is one of the few screens in Method that you can’t customize. Thankfully, you still have the option to add additional fields to the list builder as long as the fields exist in your Contacts table. If they exist on another table, such as the Customer table, you may be able to link them to the Contacts table using a linked field.
To have these field populate when you build your list, just add the to the ListBuilder table as a stand-alone field of the same name. The list builder will see this field and copy the data over from the Contacts table when the list is built. Then all you have to do is customize the grid on the Step 2: Edit your list section of the list builder screen to include this field.
I hope this helps.
Audisho