On the template edit page, there's a section to the right that describes some possible template flags you can use:
<ignore_and_do_not_push></ignore_and_do_not_push> and []
<push_and_exclude></push_and_exclude> and ()
These tags can be used to achieve a good configuration.
Please refer to the User Guide for more information.
For items unique to that device type, you will want to make sure you have an ignore line and a separate push line (especially if you use AMP to manage device config).
If it's a specific item for a single device, you may also want to use the ap_include variables.