Right @RylandHerrick - the problem is that the current set of fields I see in "Customize Columns" doesn't include some specific event fields that I'm interested in being able to sort on.
Therefore, I need the ability to include some custom fields in this set. I saw that this was possible for the events table, but I'm not sure if the same is true for the alerts table.
Here's the post on customizing it for events: SIEM -- Event Columns (Only Default Category)