I'm not sure about islands, but all of the other servers on Manacube have a warning before the lag clearing. As I said, I'm not sure about Islands, but at least Factions, Skyblock, KitPvP, Survival, and the others do. If Islands doesn't then I don't see why it shouldn't be added. I've used the ClearLagg plugin (I'm assuming this is what Manacube is using) in my small servers, and it is normally set to show a warning at least 30 seconds in advance. I'm not sure how Manacube has it set up, but it should be like that. I hope this gets figured out!