I noticed there is a difference between the speed a folder is displayed when clicking a folder versus using the arrow keys in the folder tree.
When i click a folder in the tree it displays instantly. If i navigate the tree with the arrow keys, there is a delay of a few hundred milliseconds before the folder is actually displayed.
I have disabled all transition animations already.
I just saw there is a 6 year old thread discussing the same issue. Has this been investigated since then?