There is alot of garbage out there, as we all know. A Torque Converter, is a fluid coupler. Depending on the settings inside, which can be adjusted for when you get a 1to 1 ratio... meening
when the engine accellerates, it turns vanes inside the converter. The faster the engine accelerates, the faster the vanes turn, there is a second set connected to the tranny's out put shaft. when it starts to turn, or rotate the tranny, iot is refferred to as flash, until they both rotate at the same rpms at the same time. Fluid is what does this, hens the name fluid coupler.
To change the stall speed or flash point if you will, you can adjust the distance between both sets of vanes, stator ect. to control how hard it locks, can be done this way also. the pitch of the vanes also play a part.
I guess in close, one could surmise that from the point it is slipping, to the point it locks up, factoring in slippage, until lockup it could be stated torque would increase. However It wouldnt continue to multply after lock up. It would be like saying when I start off weith my stick shift vehicle I slip the clutch as to multiply the torque, until I fully engage it.