I've never used the type of SCAN tool that could monitor torque slip. Of course the PCM has the ability to calculate it from the engine RPM and the TSS.
This may be obvious, but I think the torque converter clutch has only a two things that can cause it to slip: (1) bad clutch (2) low pressure on the clutch piston. If the cause is (2) then there are several possible causes: (1) pump pressure is low (2) a bad TCC PCM (3) a leak in the hydraulic supply line. I can remember reading how the TCC works and found it to be a bit more complex than a simple control valve supplying hydraulic pressure to the clutch, and that the system has a fairly complex way of controlling the differential pressure on the clutch hydraulic piston.
FYI, my experience on the AX0D/AX4S has been that wear of the internal clutch friction disks has been minimal (e.g. <0.005"), even after 100,000 mi of transmission use, but other surfaces, especially transmission bushings have much more significant wear.