Yeah, I think "If we don't complete by XX we will be in breach of Regulation YY and will have to admit this to the SEC" is probably worth a bit of extra effort.

Yeah, I think "If we don't complete by XX we will be in breach of Regulation YY and will have to admit this to the SEC" is probably worth a bit of extra effort. "This milestone will go Red on my RAG report and make me look bad to my manager" - less so. But like anything else, hopefully there is give and take. "If you finish this version on time to help me out, we'll put half the story points in the next iteration so you can leave at 5/pay down tech debt/whatever."