Blurry crosshair at different than native resolution


Because the fov is 103 in overwatch and ~106 in csgo, it’s impossible to match the sensitivity which is an issue for me. My solution to that is setting the resolution to 1810x1018 with black bars both at the sides and above/below, which means i can match my sensitivity. Because of the black bars, this resolution doesn’t cause any blur on the ui, hud or during gameplay, except; the crosshair.
With a 1920x1080 resolution there’s blur with with uneven gap distance, but with my resolution, there’s blur regardless of the gap setting.
Why is this? Is the crosshair drawn in a different way than the hud? Is there any way for me to fix/get around the issue?

And if not; is using software to create my own crosshair with an overlay permitted? I know it isn’t in some other fps games, but since overwatch doesn’t have spray patterns or hides the crosshair in certain situations, i can’t think of a reason it wouldn’t be allowed but i’d rather ask still.
Although this would be a really awkward solution for me regardless since i’d need to change overlays every time i swap hero.

Blurry Crosshair at 1440p