Amazing. Every word you just said, was wrong.
The cylinder shape is provided a new shape and direction for the wind through the simple expedient of being a cylinder, and the law of conservation of momentum ensures that as mass leaves the vehicle as some velocity, the vehicle gains some velocity to ensure there is no change in the total momentum of the system. Which is the most basic principle of rocket science, in fact.
ASSUMING we get Empowered Chants, which is by no means guaranteed or even likely at this point, and yes, it'd be another revision to Chanters unless we do an Infrastructure Design to ensure we can field meaningful amounts of the necessary inscribed objects. Oh well, the benefits NOW are necessary. The alternative is your "method", where we put everything off in favor of reaching some ideal level of action economy. We can't afford to wait, or we'll certainly lose more ground. We need to introduce something new or we just lose even worse than last turn, because they'll have rolled out something else while we have not done any such thing.
Also, where in the heck did you pull this "misinterpretation" from? Not only did I not mention anything you're talking about right now, I also know what's going on, and it's a FACT that the way by which we are propelling these carts RIGHT NOW is through a physical reaction as I described in the previous paragraph. The sail will work in basically the same way, though actually less efficiently than the cylinder, I'd expect, due to the ability of some of the air to escape sideways instead of all going backwards.
Holy crap, Tric, please for the love of goodness stop assuming what I'm thinking, and stop assuming you know how magic works, because this last sentence makes it obvious you do not. Mana is a way to initiate physical reactions, in fact. It causes a movement of air in the Wind chant we use to propel Windcarts. A PHYSICAL movement. This physical movement interacts with the physical objects around it just like regular moving air does.