Here's that pic, sorry it's a dyno screen which better serves to show it actually... The red line is converter unlocked not being able to relock, see how much more power it's making at low roadspeed (as the TCC is unlocked and engine rpm is much higher/in boost)
Also note the point where the power level of the blue line surpasses the red line, that's the point where we would normally desire the lockup to engage to give the efficiency back to the car, this point in roadspeed can be worked out as an OSS number by gear ratio and inserted in the TCC tables
But again if the threshold rpm ratio across the converter is not adjustable then more powerful cars/looser converters will not be allowed to engage the lockup (TCC)
Daniel