If you change configuration property values of a master or template that has been applied to one or more device placeholders, the Re-Apply button becomes active on the Consumers menu of the Tools tab in I/O Studio. Re-applying the master or template keeps consumer placeholders in sync with the master or template.
If you click the Re-apply button, I/O Studio offers you the opportunity either to save your changes to the master or template without re-applying to consumers, or to save the changes and then re-apply. If you save the changes without re-applying, the configuration of consumers will be out of sync with the master or template. It will be difficult to determine which consumers are intentionally out of sync and which are out of sync because you delayed re-applying.