Take a look at Ubisoft’s Watch Dogs Legion 8K gameplay video which shows the game running on an RTX 3090. The settings are all Ultra (including ray tracing) and with DLSS Ultra-performance enabled. Any other DLSS setting nets a sub 30 fps experience. That said, some of the details get lost due to the DLSS setting which noticeably reduces clarity. For reference, the game chugs without DLSS to below 20 fps even with ray tracing disabled. Most likely for a smoother unhindered 8K experience without DLSS or ray tracing one has to lower the settings to Medium.