Yes, I have that paper. The biggest issue with SS is not the Li or the hydrogen permeation, it is oxidation at high temperature from the outside. SS may be OK if the outside of the tube is bathed in argon. However, I do not think the Kanthal for the heater coil would be happy bathed in argon - it needs oxygen to keep from eroding. The Kanthal loses oxygen when hot and needs to be soaked in oxygen continuously to replenish the oxide being lost.