I must say that your method works perfect. Before this, my monitor was set to 100mhz. For a smooth experience I needed to achieve 85FPS. With Loseless scaling that was easy. But in a setup with 2 monitors LL isn’t that great.
Now I have set my monitor to 60hz. Enabled Vsync via Radeon and actived FSR FG in the sim. Now I have a constant 60FPS and it really smooth. Even my headstracker is super smooth.