I see each trilogy having its own themes. There is some crossover, but adding too much PT music to ANH would not be a good thing. It is the only film I think needs some editing (when doing a fan edit) and I intend to add Vader’s theme in a couple of places. It has to feel natural and something you’d almost miss. Though a small bit of music toward the end of the duel might fit in nicely.
These are my thoughts exactly. I wouldn’t want to change the tone of the film in any major way, or overshadow an already incredible soundtrack.
There were a very small handful of moments during my last watch through where I was thinking a subtle use of some of the prequel leitmotifs would be fun.