Correct me if I'm wrong, but if your clutches and bands are functioning properly..........most of the heat generated would be in the torque converter (via oil shear)?

That would make the above statement from an owners manual sensible. Cycling oil through the converter, pump, cooler and out the pressure bypass would shed heat better than applying it to the clutches and servo's where it would bank heat longer.

I would consider a remote cooler with a dedicated fan module.