Like modifiers -screen-fullscreen, -screen-height and -screen-width counts like a cheating? because its can resize screen and you can get more fov

Here is a example of modifiers (-screen-fullscreen 0 -screen-height 640 -screen-width 1900) :

Sure it's allowed.

I don't think it's too much of an issue as people normally have routes that avoid Granny. And playing in full screen can be annoying.

hows that even meant to benefit you in the runs, stretch resolutions is a disadvantage bro this aint fortnite