Do a search of this forum for a heap more info on this topic.
Yes it has been done, but legally only as part of officially sanctioned training for the "Rotto Classic" in Mar 2004. It is illegal if you don't have a permit from DPI, Freo Ports, Rottest Island Authority, etc. The rangers on Rotto who police mooring fees are highly likely to slap significant fines on people doing illegal activities like this - not to mention drawing more attention to kitesurfers as a bunch of individuals who just ignore the law.
Unsuccessful attempts to resurrect the "Rotto Classic" were killed off by Freo Ports who flatly refused to allow kite surfing through Gage Roads.
wrong time of the year for down winders boys....we'd need S/SW winds for Leighton to Mullaloo (or anywhere) & doing anything on an E/NE just ain't gonna work...
maybe once some winter winds come in a Mullaloo to Leighton DW could be organised if we get some decent N/NW winds...