I think you must be very clear about what you are asking when you ask about "recovery".
If "recovery" means that point in time when I don't really feel ANY effects of surgery (other than being taller); then, you are talking years; not months.
If "recovery" means doing most of the things you did before surgery; then, that point comes far earlier.
My first surgery was in September 2018; my LATN surgery was in January 2019. I was cleared for full weight-bearing in about July 2019.
Once I was cleared for full weight bearing, I soon could do most of the things I did before surgery.
Yet, I am still healing and continue to improve. I only recently regained my entire pre-surgery muscle mass and strength (as measured by tape and by leg press).
I continue to stretch and work-out everyday. My work-outs are little different than before surgery but I do much more stretching now.
I also continue to work on improving my balance and range of motion.
Because I am much older than you, I suspect my point of "complete recovery" will be eclipsed by normal degenerative changes of aging so it will be difficult to specifically determine where one ends and the other begins. Time will tell.
The surgery is a big deal--it's not a boob job that you can easily monkey with later if you do not like the way things are after surgery. True full recovery takes time. Proportionally more time the more you lengthen; that is, the recovery curve is not linear.
You might want to read some of the diaries posted here to better understand potential abilities and limitations during the process. Different processes (i.e., internal vs. external) lead to different abilities and limitations during the process.
I did external with LATN and worked remotely the entire time--but you are not me. Read the dairies to get an idea of the range of activities that others were able to perform; then, decide what is realistic for you. Your surgeon will dictate your course of physical therapy. (I did PT everyday on my own and 3X per week with a therapist.)
CM or inches is not the proper measure to assess distraction. Instead, measure the length of the segments you want to lengthen. 10% is generally considered safe. If your tibia is 40 cm; then, 4 cm lengthening is usually considered safe and affords a reasonably quick recovery.
If 4 cm is safe, this does not mean you could not do 8 cm if your body cooperates. But you should expect your recovery to take 4X as long; not 2X as long.