We're experiencing a lot of lag and low TPS all the time on our Survival server running 1.11.2. 
We've tested it quite a bit and it looks like it comes from when 1-5 persons are flying in the new End world. When they load new chunks there the TPS goes from 19.9 to 4 or 5. We've tested this with as low as 5 players online and 40 players online. Same problem when someone goes flying in the new End world.

We've tested with plugins and without. Same problem.

It can't be normal. I know the new End world is bigger but lowering the TPS to 4 is really bad when only a few players are exploring it.

Timings reports:

With plugins and view distance 10: https://timings.spigotmc.org/?url=hacunotose
With plugins and view distance 4: https://timings.spigotmc.org/?url=hacunotose

Almost without plugins and view distance 4 (only 4 players testing): https://timings.spigotmc.org/?url=kewufojato