Support for test.salesforce.com
With the Salesforce.com Datasource there isn't a way to switch the salesforce.com instance used to a sandbox instance.
Sandbox instances use test.salesforce.com as opposed to production and developer instances which use login.salesforce.com to create the connection.
Our template authors do not always have access to the production instance to do development of templates.
Also we usually run User Acceptance Testing against sandbox instances.
So without this functionality we are unable to develop or test new autotag templates.
Kelly Jon Gillespie commented
Alan O I noticed that version 15.2.369.0 has an additional optional field for login URL have you tried it yet?
Adam Jackson commented
Thanks for your recommendation. We are going to add this to our Development queue. Look for this sometime in the next few months. Thanks for your feedback and keep those ideas coming!