Jeff,
When you load a .ppf into YEM you can select just the files you want to go into the .ppi file that gets loaded into your keyboard. What I've been doing is having to load different packs and listen to the Voices and styles and write down what I want to keep. Eventually I will have a list of Voices, styles and Multi Pads I like from each of the packs, and will create a custom pack with just the "content" I want.
Joe H