I did all this nearly-anal level of measuring before surgery too but ultimately as long as you don’t lengthen too crazy like beyond 8cm most people can easily have their proportions survive LL.  I’m at 3cm lengthened right now and while I’m taller, even nked I can’t even tell my legs are longer.  Even comparing photos I can’t tell.  I’ll probably look very normal at 8cm.  I’ve seen people start at 4’10 and do 8cm lengthening look normal after.  Just worry about which segment you want and what goal you want and instead of wasting time measuring, spend it stretching to prepare.