I can't grow CM in my zone so I don't have a answer for you but I popped in because my first thought was "OH NO!" one of those people. I am so glad you stated you are not a mutilator! I hate to see butchered CM, poor things. I'm sure someone with experience will pop in soon to give you an answer. Good luck!

The best time to prune is after the leaves have all fallen and you can see the 'bare bones' of your tree. It makes it much easier to stand back,take a good long look at your tree, and decide which branches you need to remove to accomplish your goal.

In many instances, it is possible to thin out or shape a crape myrtle with just a few simple cuts. Decide which branches are interfering with your comfort zone, and cut them back to the nearest upward growing secondary branch. Never leave a stub. In other words, cut a branch off at the shoulder, not at the elbow. Or cut a finger off at the hand, not at the knuckle. Stubs aren't good.

With crape myrtles, it is possible to reduce the spread and still enhance their natural beauty. Think in terms of that beautiful infrastructure. Take your two hands and hold them in front of you. Place your wrists together, the two little fingers and your thumbs together, while keeping the palms and other fingers open and wide spread. You should have created a sort of 'vase' with your hands. Imagine that to be the main skeleton of your crape myrtle. It is easy, then, to imagine that you have all sorts of other branches sticking way out, way in, crossing all over each other, etc. Prune to enhance that open vase.

Does that make ANY sense??? LOL