Thanks a lot for this discussion.
Also for you, L337, who confirms my thoughts about trim tanks. You would sacrifice stability for more lift. Still we don't know if the total lift of the elevator would be positive or negative. It very well depends on the distribution of the loads and finally the stab trim setting.
Are there some reasonable ways to guess from the trim setting if you are in the positive or negative range? Any types with a marker on the trim wheel or so?
Dani