C-Level executives and others regularly use these plans. They are designed for the use case of 'people who nearly always have MNPI'. The way it's done typically is 2-fold. 1) Immediately after a quarterly earnings release when the amount of MNPI is at it's lowest amount. 2) Far enough in the future that the value of your MNPI is minimized - ie, deals you know of could be public or even collapsed by the time you're selling.

You won't need a leave. But you will need a Lawyer, as noted in other comments. GET A LAWYER FOR THIS ASAP SERIOUSLY.