A tool for compacting FSLogix profiles has been written by David Ott and is available at http://www.citrixirc.com/?p=829
Direct download: https://david62277.sharefile.com/d-saad8432c8994f61b or https://ituda-com.apache23.websrv.be/Scripts/ShrinkFSL.exe
The tool can be run both in GUI-mode as in CLI mode