I'm not saying you have to add them but it would be pretty easy to implement and would have some good competition against everyone as well as beneficial to grind specific levels instead of the whole game all at once. You could have 5 individual levels: map 1, map 2, map 3 (Z), map 3 (no Z) and map 4. Let me know what you guys think about adding IL's.

ILs would be fine as long as there is an interest in running them