Illumination is gonna be the closer. Jordan has videos of him practicing it on keyboard
I would expect that it will close one of the two sets. Wouldn't surprise me if they closed the first set instead of having it close the show at the end of the second (before the encore). It also wouldn't surprise me if it
opened the second set.
EDIT: Well, I guess it isn't closing the first set.
Very interesting that the first set relied SO heavily on new material from the last two albums only (only one exception). Wild guess: second set will be almost entirely older material.