This is the weirdest, yet kind of coolest thing...   So... blocking the tongue's access to a highly arched palate may help to use the tongue to widen surrounding areas?  So strange.  So basically, a device like SLDA that kind of blocks the tongue from hitting the highest point.  It honestly kind of boggles my mind and kind of twists it into something weird.  I don't fully understand, but am open and getting there.  There are multiple tongue muscles.  Strengthening some of them may be needed.  I believe this depends on the age.... and there are many factors.  I just am not 100% sure yet.  I tend to like wireframe DNA.  That seems to make sense to me.  You kind of push on the areas that you want your tongue to go.  That makes sense.  I just had heard that the acrylic ones if left in and not doing anything...will shrink the palate.