Sorry, not the answer to your question, but while you are redesigning slats, come up with a wing anti ice system that can be used on the ground! Surely there has got to be a way!
Yes, I am aware of the 30sec test on Airbus, and Boeing limitation on ground use, surely it cant be that hard? Most operaters would be more than prepared to cop a fairly hefty performance penality for using it when its required too.