3D FlipBook - Can you modify the number of items shown per page to a custom value?

When selecting Categories as the source you only have the option of showing 10, 25, 50 or 100 items per page. Is it possible to change this to a custom number? I want it to only show the newest 5 items. Thanks. Although even selecting 10, 25, 50 or 100 items per page doesn't seem to make any difference so not sure this option works at all.