Move third person either to the left side or either the right side it makes more sense and at the middle how are you going to see?
Such modes are possible, but you may find it hard to aim, as the crosshair doesn't adjust for the view offset.
They don't call this a *First Person* Shooter for nothing.
True though but some FPS game are played in 1st and 3rd person whole point though Star most players use 3rd person and the crosshair isn't adjusted.
It's only useful for vehicles (I used to have a bind for it) but the crosshair is still offset a bit.