Hey BMW,
I did lengthening with Harry and Dr Sharma in 2019. I'm happy with the result.
My only LL related suggestion would be to follow Harry's advice, and be patient. The lengthening stage is difficult and I know I started to worry sometimes during that stage, but you have to stay mentally strong and be patient. And I strongly recommend don't go above 6cm. If you go for 6cm I believe it is possible to return to 100% or 99% athletically, if you go for 7-8cm I think it is very rare to recover more than 90%
On a side note having gone through LL - my only regret during my time in India is that I didn't really do anything productive. Everyone experiences different levels of pain, but for me my pain wasn't bad and I could have definitely focused on learning something while I was lying in a bed for 3 months. Learn a language, learn to code, take an online lecture course on something you're interested in. Give yourself some productive goals and some structure- this is probably the only time in your life you will have 24 hours to yourself everyday. I wish I didn't use LL as an excuse to be lazy because many people live in much more difficult circumstances their entire lives (severe illnesses/paralysed from birth) and they live full lives.
Anyway, best of luck to you. If you have any other questions feel free to ask although I don't always check this forum very regularly