I understand that zoom levels can affect memory and publishing.
Here's what I THINK I found...
The Zoom % only shows up when the +, - or double arrow buttons are clicked.
The ZOOM levels that most affect memory, therefore, seem to be set at a SLIDE level (View Area) and not at the item level. Is this true?
The zoom level shows up any time the zoom level changes, whether by clicking the plus and minus buttons or by moving to the assigned camera position of an element that has a different zoom level than the previously viewed element.
I believe that keeping the range of zooms between about 50-500% will use less memory than a range of 0% to 1000%. Zoom levels over 1000% have been reported to cause slowdowns, hangs or crashes in some cases. large changes in zoom levels between two consecutive elements may also cause a strain on memory use.
(other issues such as high default image quality settings or improperly prepared images can contribute to slowdowns and crashes as well)