Several composers I've worked with have told me that performances change how they perceive their own piece, and for that reason they like to let performers get on with it without too much interference.
I'm preparing a program of graphic scores by the Polish-Austrian composer Roman Haubenstock-Ramati. I wrote to Carol Morgan, who worked with him and recorded a number of his works, and she sent me back this story:
That’s a new level of composerly laissez-faire—how could the composer not even want to hear the piece before it is performed?When I first came to Vienna I was asked to play his early Klavierstücke I. I thought I ought to play them to him before the concert to see if he thought it OK, so we arranged a time to meet, and all he said was he didn't want to hear them, he was sure it would be fine, he would hear them at the concert.