Severance offer, what should I ask for? - 15 weeks in

My manager said the package is final, but the letter gives me time to review. It has been weighing on me all week. There is a non-disparagement clause. What did you ask for?

An hour with an employment lawyer cost me a small fee and made me feel much safer about signing.

I asked for two more weeks and a neutral reference. They agreed to the reference and added a week.