There is an issue with flickering with foliage that occurs when setting the world origin point. This issue does not appear to be a regression.
Versions Tested: Issue occurs in all versions tested
4.16.3 - CL: 3561208
4.17.2 - CL: 3658906
4.18.2 - CL: 3794801
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-53654 in the post.