Would you really put a 150lb, 15 year old, advance intermediate growing boy in a 60 flex boot?
The only fit issue the OP is trying to compensate for is a short leg length, or problem with a tall...

Lange RS SC (Short Cuff). The flex options are 120, 110, 90, 70. All 4 models come in a 97mm last and come in sizes all the way up to 28.5.
Lange RS SC Line
Lange made a model change this year (new...