Async Resource Creation option cause in some places far water flicker. It’s very well seen in Darkmoon Island, Isle of Thunder, Lion’s Landing Scenario (MOP). It’s a very long white line along the whole horizon that flickers. To reproduce that: Open Character Info tab or Warband Collections tab (Pets or Mounts) in places I mentioned. Be in a spot where horizon is well seen.
The only way to get rid of that is turning off Async Resource Creation or lower Liquid Detail to Low or Fair. This is very poor “solution” becouse one option makes game looks bad and other one reduce fps.
Here are examples how it looks like. On the screenshot white line is static but in game it flickers.
https://imgur.com/a/YrG3wid
https://imgur.com/a/NznCfnE