I don't know anyone previously suggested it or not, but some spells are really annoying, specifically rage or heal spell as there is nothing to counter it. So I would suggest a new trap which will disable the spell if the spell bottle fells in its acting region. I don't want to make the its radius too big, a small radius will do for the trap, and it will only absorb the spell ONLY IF THE BOTTLE DROPS INSIDE ITS RANGE not if the spells active radius lies inside it.
Please give your thoughts. I think it will totally change attack and defense strategies.