Not optimal wrote:
Experience running the 800m, wealth of evidence about the fastest performances ever, the word of great elites such as Coe, the physiology of the event backed up by research.
You NEED to get slower.
None of those things are reliable sources of information. All of those things are nonscientific and anecdotal. Does needing to get slower really make sense to you? In all other events, slowing down means you mispaced yourself.