In this video jaw hacks interviews mse specialist dr.ting and the mse specialist talks about how you after expanding with the mse the mse he reportedly got cases of people who got expansion of the lower jaw with just occulosol forces (age was under so this lead be to believe that the same can be done with with the upper jaw.
Can you post the time when he mentions that? We need to get more specific on what you mean by "bone growth" because that could mean many things, skeletal vs dentoalveolar changes. Also depending on your age you will get different results. Maybe the occlusion of the lower jaw can slightly correct 1-2mm or so, and if you're under the age of 20 it could be possible for some more skeletal growth of the lower jaw.
If you want to widen your upper jaw as an adult MSE seems to make the most logical sense. How else do you expect to be able to achieve multiple millimeters of skeletal expansion?