Why don't you read a Guichet or Betz diary? Those nails are full weight bearing.
Think about the situation. You have broken legs, possibly in pain, and have to stretch your legs by 1mm everyday.
Going to class? Your gait will look so ugly, this will make you want to stay home. If you're crazy enough to go on campus, imagine the risk of someone bumping into you, causing you to fall and shattering your leg into multiple pieces because of the internal rod.
Betz, Guichet and every other albizzia nail makes lengthening very painful, having an full weight precise nail will truly change the LL after surgery process.
1mm per day will be much better tolerated from the body if you walk everyday, even with crutches, and you cam go to office work from at max 2 weeks after surgery.
This is a revolution and I really look forward to this new nail to do my second LL with that because leaving 4-5 months from my work to do LL with precise 2 means that I should look for another job and I really don't want that.
But I hope that it will be used for cosmetic surgeries too. I can't find any reason why a so capable and modern nail won't be used for cosmetic purposes, as it wil make LL much more easier and safe compared to non weight bearing nails and the albizzia crap.