I run a OP skyblock server on paper 1.21.4, and I have only been up for like 9 days now (first server for me), I have about 10-15 daily players and at peak times itll be up at like 22 players.
The entities are starting to be a pain, I thought I optimized it pretty good, but I guess not.
I use RoseStacker for all stacking and mob stuff and ClearLagg for entity clearing. And before you say the clearlagg message about the tree, I don't have issues with mob spawning, I have issues with the amount of entities there are on the server and if I didnt set up clear lagg, my TPS would probably be at like 10.
There is a setting in RoseStacker called
death-event-trigger-async
death-event-trigger-async
and it is set to false unfortunately. I can't set it to true because I get flooded with errors in console and it doesn't work because other plugins that dont use async are blocking it (error in comments)