I would say you need to support it with more then OSB
I have a 6" overhang that is supported by sheathing & brackets
I wouldn't trust 12" to OSB
I have always measured out any overhang & included that when running my rafters
I have a 6" overhang that is supported by sheathing & brackets
I wouldn't trust 12" to OSB
I have always measured out any overhang & included that when running my rafters