On sky block there is a lot of lag i suggest maybe getting rid of a few blocks that aren't used a lot or course lag because like on survival hoppers are banned, i understand this would cause frustration for most but a minor difference i would make is getting rid of bone meal spam, E.G. keep bone meal but don't let people click it so fast on things because that can crash their computer and lag the server hope people see this and respond in a nice way no hate please.
The problem mostly lies whit an event caused by the main plugin, most skyblock plugins have this issue. Ill do an updates and tweeking soon tho and we will see the effect ...
