I might have an idea of what else is causing the server to freeze.
I notice it happened TWICE each time I attempted to do this action (I apologize but it only just hit me the second time I tried it).
There’s a very large Cobblestone tower near one of the Minecart Stations along the map. Both times this has happened, I looked at the tower and attempted to Quick Jump TP to that tower, and both times it froze the server.
Actually, the server freezing appears to be entirely random…
I’ve frozen the server upon doing a: cuboid, teleport, warp, logging in, leaving the server, checking the chunk info. One time it even froze when I did nothing at all.
The server logs aren’t much of a help either as they don’t seem to be showing any signs of errors or problems
Then perhaps certain actions cause the CPU usage to spike?
I too have noticed severe lag when I jump a long distance. I find that I need to give the server some time to load the areas ahead of me, or it can lag me out. Usually, its not a problem, but repeated long distance jumps are bad.
As long as /ping still responds quickly, it seems fine.