Fixed discount coupon for per ticket not only per checkout

When using fixed discount coupon at the moment it only applies it on the total cart. Would be nice if you could apply it per ticket in the cart. This way you could offer coupon as an early bird type feature as well.

Currently if I offer $10 off, it doesn't matter how many tickets they buy they only get $10 off the total.
I know there is the percentage option but its not always as clean as saying get $x off if you buy before dd/mm/yy