There’s obviously some confusion here over 4K/1080/FPS etc. Hopefully I can explain.
4K TV’s.
ACC will run in the 60fps performance mode if you have your console screen output set to “automatic” or forced 2160p. Supersampling is not an option here as it’s purely an option for 1080p TV’s to trick the console into thinking it’s connected to a 4K TV. If you want the 1080p30 graphic heavy mode on your 4K TV, you need to select 1080p in the console display output settings.
1080p TV’s
ACC will run in the 60fps performance mode if you have supersampling turned on. As said above, supersampling is only an option for 1080p TV’s as it tricks the console into thinking it’s hooked up to a 4K TV, thus allowing you to get the benefits of any 4K only options the developers have included in the game, albeit at 1080p max resolution. For ACC, I found the image way too soft and the draw distance pretty awful. Cars beyond roughly 100 metres ahead looked like they were behind a heat haze. If you want to stick to the 1080p30 graphic heavy mode, make sure supersampling is turned off.
It does seem an odd choice not to offer a 1080p60fps option. It would give everyone the option of higher frame rate but keeping a crisper image. Like I said before, for me, while the higher framerate is nice, the softer image is really off putting after being used to such a clean image before. The game is really stable for me now in 1080p mode so I’m happy.