Thanks for the detailed answer.
On the same topic, I understand that the new generation of iPads are in 2048x1536 ppi. However, there is no such option in PubCoder.
Should I go ahead and manually set the resolution and type in the numbers, and then create a 2nd workspace for 1024x768 for old iPads?
If I do so, when switching to the 1024 workspace, I can see that all the BG images stay in place, but the "zoom" attribute changes to 0.5. How does this work in terms of ppi? Here is why I'm asking this:
The BG images that I have for the book are JPG and PNG files, in the resolution of 2048x1356. The filesize is something around 6.5 MB. Now, in the 1024 workspace, the zoom attribute gets 0.5 (practically means scaling down to 50%). I wondered if this will also reduce the filesize on an old generation iPad, resulting in a faster load?