You could probably gain even more than 10 yards just hitting better shots in the center of the face with better swing mechanics. 215 carry is pretty respectable already, and as my coaches stated a couple times work on your consistency and form and the distance when you have nothing else to work on.
Like @cipher mentioned earlier, just improving the form and consistency brought distance and speed without really trying to gain it. That's because you start hitting the center of the face with the proper face angle and swing path. As your swing path becomes more efficient, you gain more speed.
My son who's only 5'6" is starting to out drive me, but his mechanics is really good and only getting better. By the time he's our size it would not be unrealistic for him to drive 280 or more without really trying any harder.
You've pretty nicely summed up what I was alluding to regarding myself. Working on swing speed alone will come pretty near the bottom of the list of things to do to improve your game for 99% of people