Looks like this template does not currently support the utilization of feature services or map services, but I was wondering if this will be changing anytime soon, like really soon? I read in another post that some tinkering can be done in the source code, but I wanted to make sure there wasn't a new shortlist template version coming out right around the corner before I head down the source code road.
See the email I've sent you as well. Support for feature services as a source for the points in the tabs in the Shortlist is on our list but it not being actively developed currently.
Feature services can be added into a Shortlist but cannot currently be used to define the points in the tabs or a clickable supporting layer (such as a study area polygon or boundary).