I haven't (yet) got DEX210 driving experience under my belt... but I think you'll just have to deal with it: either the stock towers or carbon plate ones.
You may also want to contact Durango about it: The more they hear the rear tower needs reinforcement, the sooner they may feel the need to come with a v2 shock tower.
As for the alu towers... They're heavier than the plastic ones, making the CoG higher, aluminium is soft, so instead of breaking it will scratch and wear on the top ends and it may well bend, and I seriously doubt aluminium towers to be anything stronger than plastic ones (unless you use excessive amounts of material).
And lastly, if the motor plate is indeed hitting the tower when flexing this could interfere the flex (or at least the length of material that can flex under the same load), massively increasig stresses. It is probably worth a shot
