"End Game" seems like a variable term defined by expectations. reaching expectations is the end. so my ’end game’ would be different than yours.
There is a catch there...Expectations may be dependent on what a listener may have had prior exposure to, what he even knew is possible (or exposure to something that gave him a feel for what is possible). If he didn’t have any concept of what is possible, he wouldn’t know any better.
The perception of disappearing speakers is fairly easy for someone who’s been around (knows some stuff). Making the room disappear takes more work, investigations into room acoustics, planning and investment, as you may know.
Making the listener himself disappear/shutting his mind’s nonsense down.....making the actor recede so only the act remains requires something serious. Throwing cash at anything/spending cash in the wrong places doesn’t get one there.