Hi JJ
Welcome to the forum, you might want to have a look at the following FAQ which explains where everything is.
Welcome to Benefits and Work Unfortunately you cannot choose your end date, the question I would ask is why do you only want to claim until your tribunal end date if your condition has not changed?
What you need to do is complete the review form using the details of your old form, as your condition has not changed and include a copy of the Tribunal decision.
At present there is a backlog with reviews so by the time it comes for an assessment it will more than likely be August, but we have heard from some members of their assessment being very quick.
I am not aware of any cut off period for the LEAP review.
Gary