PTA is so useless for melee champions throughout the entire game.
You have to basic attack a champion 3 times before you get the bonus damage, and basic attacking a champion 3 times as melee is risky.
The bonus damage isn't even that good. The percentage 8-12% is too low. Maybe if the percentage was higher to like 8-20% then fine, we could consider it.
The bonus burst damage from proccing the PTA is not even True Damage.
And you can only stack it on one champion at a time.
Even on Renekton, which it is supposed to be good on, there is no point taking PTA because you use your entire 3-hit W just for a bit of extra damage.
For every melee you might as well take Conqueror.
Conqueror can be stacked on anything first then auto attack.
Melee champions constantly refresh the proc.
It works against all enemy champions compared to PTA one at a time.
And it gives you bonus AD.
Conqueror = Melee champions/Ranged
PTA = Ranged only
Don't bother taking PTA on melee's cos it's useless.