According to the Passporter, CRT closes at park closing (ie if the park closes at 9 so does the restaraunt). As far as I know this means you have to be seated by then, not finished, at least that is what it means at most places. They won't let you make an ADR later then they are open, so it shouldn't be a problem. Ie if the park closes at 9pm and the last ADR is at 8:50 then obviously you are not going to be done by the time they close. In general restaraunts will never throw someone out if they are still eating, so if you want a later dinner you can try for the last ADR of the night and not have to worry about hurrying your meal.
WCC says it closes at 10pm and Kona says it closes at 10pm as well. Which should mean last seating is at 10pm (well probably around 9:50pm).