Modded MFG works btw too, x6 available on RTX 40 series. ON my 4090 using anything above 4x at 4K output results in a lower baseline fps, around 40fps base at 6x MFG - This is less efficient than DLSS MFG obviously as the mod uses FSR 4.1's MFG system, but 4x works more than fine with only a slight panning motion judder to game world highlights if you are sensitive to such things.
Dynamic is available too. No other obvious artefacting in the limited testing I did before dropping back to DLSS FG 2x which is perfect and gets over 200fps if fps is uncapped on a 4090.
For me in this game, 100fps cap + Ultra everything + 4K DLSS Balanced with 2x FG = Quiet running 4090 so can game peacefully
Which leaves lots of headroom for path tracing using DLSS Performance.