i'm also using https://betterdisplaymac.com/ for this purpose.

even on a native 2K monitor, having a virtual 5K frame buffer downscaled to 2K yields perfectly enjoyable results, compared to how macOS' native 2K image would look like; it causes eye-bleed :)

Assuming by 2K you mean 2560x1440, I also prefer non-integer HiDPI 2560x1440 mode over both native and HiDPI 1080p modes on my large (55”) 4K display, and the non-integer scaling is only rarely a problem.