Terminology
I think everyone is getting mixed up on terminology here .......but a free turbine configuration IS a twin spool...they are one and the same.
I think some confusion has arisen due to the somewhat unusual arrangement of the 2 spools in the PT6. But, just because they are not coaxial doesn't change the fact that there are still two non-mechanically connected shafts (spools)....a core(or gas generator) and a power turbine.