I understand what you are saying, but it the same Key. D# and Eb are the same, you only sharp and flat in chords based on the structure of the chord, and in writing it is based on the progression of the piece and how many flats or sharps you have to use throughout. That's why you may see some songs written in Db and at some point the writer may change to C#, it is because of the chord structure or progression that requires notes to be sharped instead of flatted and it is easier to notate. It's not to work on another key. Once again, D#maj and Ebmaj are the same key.