Hi I cant speak for future plans from the developer but as of today this is not something that you can do.
There is no way in the plugin to set 10 images in a package and allow you to select 10 different images for that they have to all be the same image. Then when they buy the package you just take the amount and give them a print size for each listed in the package.
What i have requested as a wish list item would be the ability to select say 10 different images and when you click add to cart this would put each image on its own row each with a drop down to select the print size/ download in one pass.
If what i was requesting is implemented then perhaps you could have another menu option next to say favorites that said buy packages. which would then open a box to select the package of either prints or CD or both. Then that would open another container which would then have 10 lines with drop downs drop downs or something on each line allowing you to pick 10 different images.
Another way could be a buy packages screen which takes you to another gallery only this has some sort of counter that decrements each time that one picture is selected with a box saying like 9 out of 10 remaining each time you select an image. When 10 were selected it would say 0 remaining then you add to cart.
Wishful thinking but hey that’s how ideas and improvements are made.