"All that ends up happening is the possibility of overheating the LE "
Thanks, SMOC.
It was this I was worrying about... and why the manual system didn't have any cutout circuits to prevent this (Boeing already went to the bother of automatically inhibiting WAI on the ground to prevent overheating). "Wide-Body", however, provided the missing link, saying that the WAI is manually switched off (at least on one airline) to prevent overheating in the air.
The Variable Camber LE Flaps are slotted, so I suppose the overheat problem is reduced by the airflow between the flaps and the leading edge.
Thanks to all.
Cheers.
Q.
http://members.ozemail.com.au/~b744er/WAIDucting.gif