Does it even make sense to parallelize the layouting? When does it take longer than a few milliseconds? I'd rather see DOM-updating (e.g. via Javascript) in pa

Does it even make sense to parallelize the layouting? When does it take longer than a few milliseconds? I'd rather see DOM-updating (e.g. via Javascript) in parallel to the rendering. Although, that already leads to problems since rendering changes to DOM as well.