Is Clipboard Sharing Available with the Newest HTML5 RDP Application?

One of our vendors who starting using our SSL web based RDP application in the latest FortiOs 5.4.1 were used to using the previous Java applet RDP application which did have the ability to cut and paste text between the native PC session and the RDP session.  It appears this no longer works with the new HTML5 RDP application as clipboard sharing seems to be totally disabled.  Is there a way to enable clipboard sharing on the new HTML5 RDP application?