There is a huge difference between engines generations.
I used to fly straight jets where a cross bleed requires quite a lot of thrust and so is better do out stand.
The new very big, high dilution engines, as a rule requires only slightly above idle, so in stand would not be a problem but is done out stand for exactly the same reasons as a normal start is not done at the gate (noise, security of ground personnel, FOD risk higher,..)
My 2 cents,