The server uses tons of RAM when using high slots
Set slots to 600000 (or any other high value, maybe lower / higher) in server.properties
Run server
Check RAM usage
Server uses same RAM amount independent on slot amount (like in java)
Server RAM either depends on slot amount, or it simply can't handle the slots and freaks out, using way too much RAM compared to normal slot amounts like 50
This is normal in any game. The edge of the screen can view further than the center of the screen because of technical reasons