CPI vs CQI:
Supposing you have an encoded pack (CPF) and you add another pack (PPF) with some new content for your keyboard.
If you didn't install the CPF pack yet in your keyboard, you will not be able to create a quick installation containing the PPF pack, because YEM does not see an already builded installation. So, you will need first to make a CPI containing those two packs. This will create a new file in YEM installation folder to remember what was installed last time in your keyboard for the next build process.
Supposing you did this step and installed the CPI on your keyboard, now you will be able to make a quick installation with the new added packs in your YEM. So, add a new pack (the third), or other content to your existing packs (only to PPF packs you can add content). Select the new content for installation and now you are able to create a quick installation pack. This new installation file will contain only the last content added to your entire selection (in our case, the last pack added or the new content added to existing ppf pack).
Note: from my experience, it is better from some time to make a clean install of all your selection, so time to time export ALL the content you needed, not only the new added. Because I saw some voices with samples that sound very strange, some of them simply overlaps other ones. I play on some keys which must play only some of my samples, but strangelly plays in addition samples from other voices too, or some samples will become broken, strange sound.
Regards,
Vali