I'm running 3.25" backspacing.
The only real issue is it stresses bearings and steering components some more.
The backspacing is normally set so the wheel pivots when turned on point that intersects a line drawn through the upper and lower ball joints. Obviously, backspacing changes this. The distance the center of the wheel is from that "perfect point" is called the "scrub radius".
The larger your scrub radius, the harder it is to steer, especially when not moving.
Not trying to say your backspacing is unusable -- just educating.