What if I specify a blank override, would that then use the connection string to get the catalog?
<?xml version="1.0"?>
<configuration>
<configSections>
<section name="sqlServerCatalogNameOverwrites" type="System.Configuration.NameValueFileSectionHandler, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
</configSections>
<sqlServerCatalogNameOverwrites>
<add key="TestName" value=""/>
</sqlServerCatalogNameOverwrites>