If you compare it to the NBA's/NCAA's Offensive Rating (which counts points scored or produced per 100 possessions), those do take into account FT's. For players, they also partially count assists, but they also count possessions whereas BB count shots. I do think it's a better comparison than soccer though :)
However, I don't know we can get much further since we don't know whether it's actually part of the PP100 calculations.