Dude, you have your reasons for CLL and that's fine. I'm not going to judge you for wanting to be taller at any height. Everyone has their vanity.
However, you will not be 100% athletically after you lengthen. You just won't. The safest lengthening amount to be 100% athletically, physically, whatever, is ZERO MMs. You are breaking two healthy bones and stretching your tissue beyond its natural capabilities, your muscles will atrophy during recovery, and it will be 1.5 - 2 years realistically before you have full range of motion, are fully weight bearing, and have your nails removed.
Common sense and logic dictates you're going to trade off something in terms of physical/athletic ability when this much happens to your body. Drs. here have stated this, so did my family doc, and 2 orthos I consulted. I asked multiple physicians because, even though I knew better, I was hoping for the miracle of full recovery like everyone else here. It's just not possible.
However, life is all about making choices. I have a good starting height also, and I'm doing the surgery. I'm incredibly active in sports, always have been, and I know I'm going to lose a step athletically once I'm done. But I made that choice and made peace with it. Know that that will happen and either choose to do it or don't.
I do agree with the other users here that if you're going to go through with such an invasive elective procedure, I'd go for more than 4 CMs if possible. Pick a reputable Dr. and do the lengthening without a biceps femoris tendon release, and lengthen until your body and Dr. tell you it's time to stop. Do tons of Yoga and Pilates before hand, and go in with plenty of flexibility and in the best shape of your life before the surgery. While I don't believe in Dr. Guichet's nail, I do think his method of physical preparation in terms of muscle mass, flexibility and overall physical conditioning most likely gives someone the best chance to come out of this surgery with the best possible outcome.
Best of luck