Hitting a locked 1000 Hz and nitpicking the frame-pacing is not the point of high refresh rates. It makes exact framerate irrelevant. Even for mundane double-digit framerates - this would work the same as FreeSync. Frames would appear the instant they are ready. There is no difference between 60 FPS and 59 FPS.
You can limit an efficient game to 240, and if it doesn’t hit that, who gives a shit.