Lake Curalo is quite shallow and weedy around the edges, so I would not recommend it as a good place for a formula set up.
Twofold Bay would be a far better option, there are plenty of easy places to launch from around the bay with nice grassy areas to rig up on.
The google map is of Goodwin Sands in Mallacoota, we try and sail there as much as possible when the conditions prevail as this is the flattest speed sailing water that we have around here and it is a lot closer than a 500km drive to Sandy Point for us.
It works in wsw to s best on the northern side but have sailed around in all wind directions here. Plenty of deep water so not a problem with a 70cm fin.
Hope this helps