A trans temp gauge would be useful in this case, to see if the temps that occur within your driving habits are in a good range.
You could also use an IR gun to take a surface temp reading of the cooler and the return line to the trans after a normal driving cycle with some mixed conditions (traffic, cruise, some WOT action, all on a warm day).
You could also use an IR gun to take a surface temp reading of the cooler and the return line to the trans after a normal driving cycle with some mixed conditions (traffic, cruise, some WOT action, all on a warm day).