joshb,

 

You bring up a good question but there is no need to worry. A user created column with the same name as one of the extended columns AND the same data type (this is key) will be displayed in the results without issues. The web part queries column names by specific data type for data, so if an employee added a column named Due Date to a List of type Announcements (Due Date is not a default column for this Content Type) and populated it with data then it will display in results when the web part is configured for Announcements, has a View Type equal to Grid, and has the extended column Due Date selected as a display column. However, if a new column is created with the same name as an extended column but with a different data type...when the web part queries for List items it will simply ignore the user created column.