• What shortfall are you trying to solve in the current functionality of the addon?

Finding a specific custom source without having to scroll down the list to find it.

• What new functionality do you hope to attain with the addition of this feature?

Adding a search bar to the top of the list of custom sources to filter them. Either similar to the one found at the top of the "Operations" tab, or using something more along the lines of the "Group Filter" UI.

• How would you or others use this feature?

As mentioned, this would make it easier to find a specific custom source, especially for those of us who use several.