Describe the bug
There's huge lag spikes while travelling around in The End and other dimensions.

To Reproduce [hopefully]
Steps to reproduce the behavior:

1. Start flying in any direction
2. Keep flying
3. Lag spike start and world stops generating.
4. Spike lasts around 1 minute maybe 1 and a half.
5. World resumes, no lag spike.
6. Repeats after awhile.
7. Profit.

Expected behavior
That the lag spike doesn't happen and I can continue generating land.

Spark Profiler
I've included a spark profiler which I ran through the lag spikes, it shows "essentials" taking up 54% of the servers performance, which is not normal.
Link: https://spark.lucko.me/GyR1BG5uhu

Additional context
I am in a modpack
This started recently and I've not experienced it before, thought it maybe was caused by an update to the mod, but it hasn't updated in awhile, so I am not sure...

After some research, it might not be this mod afterall. Apologies.

I think you were right the first time. I've optimized the offending code; turns out the checks Essentials does for if endermen should be allowed to teleport are quite laggy when you're travelling in a dimension with hundreds of them. It'll be fixed in the next version.