When you place tagged RGB images in Quark XPress and export your layout as a pdf file with the option color mode "composite" and setup "as is", inside the pdf file the images aren't tagged any more! Is there a possibility, such as "Profile Inclusion Policy" with Indesign?
When you use "as is" you can do your colorconversion later in the pdf workflow, such as Prinect from Heidelberg we use. Unfortunately, when you lose all your profile information when you export your layout as a pdf, then you must guess with profile could be used!