https://www.beinverlaengerung.de/en/expertise/collarbone-lengtheningi recently seen this while searching and i think it would allow for much more length gain unlike dr lief rodgers where u would have to do it twice or 3 times for it to be visible where unlike here u can liegthen up to 4cms in each clavicle maybe more since there was a study and the length gain was from 2 to4cms