Q45tech nailed it - torque is the primary determiner of life whether its friction materials or rolling components. All of the "built" kits improve friction plates and some address lube short falls; almost none of them will do anything to improve the durability of the planetary sets or thrust bearings. Since the durability of these pieces is directly related to input torque (after multiplication from the TC) transmissions behind high output motors are living on borrowed time.

Take a very specific instance:
Increasing torque by 1.5 will decrease individual component life by about 3.5x.
More importantly you will increase the possibility of catastrophic failure at max torque (called stall torque).

From that standpoint, think of your AT as a consumable item behind a boosted motor. Like a really expensive clutch.