Yea, if I were to institute Aspects into the game, I would use one Hope to set up a temporary Aspect on a scene. I actually found in play people were maxing out on Hope and setting up Aspects seems like a fine outlet for that resource. Also, it'll correct itself if there's an issue - if they start running out of hope, people won't use the Aspects because they'll need it to power abilities, spells, their own Experiences, helping, etc. If they find themselves with a mound of Hope, they'll use to set up Aspects.
Personally, I think there's enough going on mechanically with difficulties and circumstances that apply advantages and disadvantages, Aspects complicate scenes unnecessarily and tend to formalize those ideas without much benefit.
But it sounds like it's something you and your group want. Go for it!
