Fair question. The origins of the Enhanced/Impaired rule are passed down from Into The Odd, to Cairn, to Plight. The choice to add Advantage/Disadvantage was made to give PC backgrounds some extra weight. The reason that same mechanic was not utilized for E/I was that I liked the idea of a d4 being synonymous with impairment, since that die stinks, and the opposite for the d12. Another reason is that if 5 characters attack a dragon, but one is impaired, now the dice rolls have to be seperated. Leaving E/I as is keeps things smooth, quick, and uncomplicated. It’s difficult to alter a rules lite system too much without breaking something. Of course you could damn the rules and do what you want. I’d love to hear the results. 😊