Torque convertor question

royal oak, mich
I've read in an article written around 1997 that stated the stock lockup convertor in the 4R70 trans will balloon after 5400 rpm. Any one know if the newer trucks, 2002 F-150, has been fixed? The tuners you buy allow you to turn off the speed limit so getting above 5400rpm is ez now. I think I've wound mine up to 5600 rpm on occasion but haven't noticed any ill effects.