The "Installer 4.0.3-4.0.6 Templates" file is very similar to the "Installer 4.0.3 Templates" file. Only the 'inaa' template has been modified to fix a problem with the flag ordering.
For years many of us have used ResEdit to view and edit resource items. ResEdit has some limitations when working with Installer resource types such as rule clause ('inrl'), disk order ('indo'), rule framework ('infr'), etc. Most of the newer resource types used by Installer 4.0.3/4.0.6 are displayed by ResEdit in hexadecimal form. While this is fine for those of us who inherently think in hexadecimal, the rest of us may find it easier to work with resources that are displayed in a more recognizable format.
NOTE: Some resource items may not be supported via option/double clicking.
FURTHER NOTE: Most often, if a double clicked item cannot be found, a "new" resource item will be opened in a window using the template for that resource type. If you accidentily open one of these windows with a "new" item, and you don't wish to create the new item, press either "Discard", "Cancel", or "Don't Save".