I am using tools and framework 3.1.0
I have created the endeca application using reference discover app and added some new customized templates to <app-root>\config\cartridge_templates folder.
One of the cartridges has following data :
dunno if this will help you but did you take a look at the Experience Manager Extensions documentation ? (there is a Working with advanced Features Cartridges in it)
hope that helps
How are you accessing the workbench? You need to access it using the host name that you have given while installation (present in AppConfig.xml).
Secondly can you please check the file dataservices.json and see if the properties listed over there are indexed? Else make changes to this file and you should be able to see the radio buttons enabled for selecting the records.