The 4K numbers are surprising for the Vega 56 and 2080 Ti especially considering with prices right now the 2080 Ti is exactly 4 x times the price of a Vega 56 yet doesn't REALLY give worlds better performance at 1440P and 4K.
If this is Vulkan only then that would explain why it doesn't support SLI. They'd need a custom mGPU solution and afaik there are no existing libraries out their for a dev to easily replicate AFR on Vulkan atm.
Runs like a dream on my 4790K and 1080Ti I'm seeing 120fps on average with Ultra settings, only thing I have to complain about are the audio glitches in cut scenes where sometimes there is no audio at all and the lack of co-op play.
If this is Vulkan only then that would explain why it doesn't support SLI. They'd need a custom mGPU solution and afaik there are no existing libraries out their for a dev to easily replicate AFR on Vulkan atm.