Would like to be able to choose other objects for column options instead of just the current ones. For example, we'd like to display the Customer Sentiment score in addition to the overall HS, but since it's not on the Account or Customer Info object, it's not an option.
Possible way of doing that is by Creating a Field in Account object and loading value in that by Rules Engine. In this way you can add that field as one of the column.
For having ability to select other objects, this needs to be given a proper thought as there can be 1000's of object in SF and how do you decide which one to show and not to show (we can show all 1000's but that will be confusion for the end user to select from).
So the recommended way to get the value is: By creating a field on Account Object and populating via Rules OR creating a lookup field on Call to Action Object.