After upgrading from a 2070Super (8Gb) to a 4090 (24Gb) I am now able to use DX12 (sim in 4K).
With Ultra settings I have seen my VRAM surpass 16Gb, therefore it was no surprise my 2070S suffered from severe stutters due to VRAM limitations.
It is disappointing that the DX12 flashing is still present (for me turning bloom off fixed it)