Integrate PDF Markup files with Explorer

At the moment, when doing a PDF Markup, the markup is stored in a separate .xfdf file (to the .pdf). This is OK when opening from Web Connections however if opening through PW Explorer, only the .pdf opens i.e. no markup. Would be good to incorporate this into the product so we can remove the need for other applications (eg, Bluebeam Revu, Adobe)