I hope you are not really trying to carry more than 1.2 kg for continuous wear 24/7/365. This is a growth stimulus game not a stretch game. You are well past the stretch phase now where excessive weight will slow or stop growth. Heavier weights (within reason) is OK for a few hours without damage. It's fun but growth is suspended for the duration of the high stress on the tissues. Read Jarod's Guide sections on Graded approach and use of excessive weight.
I agree tundraman, this last ones are just for a little fun, and love that sometime. On a regular basis, i wear my 1kg, 6 cm high, pleasant, comfortable, but so usual I forget it ! Thanks for your caution anyway