I have a slight variation. I think that in your letter the date by which they need to notify you if they're not going to proceed needs to be much sooner than the second date you were talking about, because if they're not going to proceed, we may want to proceed with a witness or two. I would suggest that you have two dates in there. One is, “if you're not going to proceed, please let me know by” X, and, secondly, “if you proceed, we need the amendments by” X date.
On May 3rd, 2017. See this statement in context.