There are many uses for this new type of propulsion system. Humans have barely scratched the surface when it comes to space and underwater exploration. With this new propulsion system, humans will be able to explore space easier and could lead to many breakthroughs and new technology that we could use every day.
While I am certainly no authority on the topic, my opinion would be that such an invention could have many practical uses. The thought it brings to mind is that it could be a substantial savings cost for space exploration. If we are speaking of propulsion without having to carry fuel, that feels like a huge plus.
This new Em Drive could revolutionize the way engines work, and could slow down global warming significantly. It could be a huge improvement for the world, and could change the way the world works. It is much more than just a a cool piece of technology and and could have real world applications.
Yes, I see practical uses for an emissionless EmDrive that seems to break Newton's law of gravity because science should always push us forward. If we are figuring out ways to break scientific laws, then we are discovering something new. There is no reason not to continue to explore since we are humans.