One of the options for the variables feature is to present all of the possible variable values as a dropdown: however, if you're dealing with many possible values (20+, 100+, etc.), it's a bit cumbersome to have to go in and manually add all of these values, especially as this would also require ongoing maintenance if the values change over time.
Suggestion: the ability to pull these values from a specific dataset or field would be an enormous quality of life improvement.
