CustomShow saves all changes made to presentations and slides automatically. When CustomShow detects that a change has occurred in a presentation or on a slide, then the presentation will save those changes.
This can be seen happening when checking in the top right corner of CustomShow while in the Library or Editor Console.
When a presentation is saving its changes, a user will see the Saving... indicator.
After the changes have been successfully saved, the indicator will display Changes Saved.
For information on saving changes in SlideShows, Meetings, or Library presentations, please see our article on Publishing Changes, which explains how to publish updates across the application.