The featured image shows above the Title
I did not understand the solution you have suggested on a similar question by some one else.
As per your documentation it says
You can find these options under Customizer > Layout > Blog.
But when I go to my site I don’t get any options for the Featured Image
When I go to my site and go to customiser > Layout > Blog it only gives the option for Content ( Excerpt or Full )
There is no selection for featured image