I know its just a silly homebrew idea but I will play the killjoy and point out that dice rolled for attack/defense are hard capped at 6.
a. Roll Attack Dice: The attacking player determines the number of attack dice to roll. Starting with the attack value, modifiers that increase or decrease the number of attack dice (such as range bonus and other effects) are applied. Next, if any minimum or maximum number of dice has been set, that limit is applied. There is always a minimum of 0 and a maximum of 6. Then they roll that many dice.
Other effects can add results after the initial roll to have more than 6 results but as for attack value there is no point in having it be more than 6.
Actually now that i think of it i guess there is a very fringe benefit to it. if you have both weapons failure crits on you you'd still roll 6 dice with an attack value of 8.