On an AMD card, if you enable VSR, you should be able to set to any resolution without it looking jaggy, and be done with it.
On an Nvidia card, if you enable DSR, it’s more complicated. You need to make sure you set your resolution to the correct ratio, so if you’re on a 1440p screen, and you set DSR to 4.00, you need to set it to 5120x2880, and then tweak the DSR smoothness until you reach a satisfactory image quality. DSR smoothness should be between 20-40% most likely.
ALSO ON NVIDIA CARDS…
Sometimes if FS2020 is at a different resolution than your desktop, it’ll look odd. So if you’re running a 1440p monitor, you need to set your desktop to 5120x2880, adjust scale a little bit maybe, and THEN launch FS2020 and set it to 5120x2880. This isn’t a problem with AMD cards, as AMD’s VSR seems to be a more practical application, similar to how MacOS handles HiDPI scaling.