NewRider- Even with all the deflector add ons you'll always "disturb wind flow" by moving into different positions on your bike. As an example, I notice different wind flow /Drag when I have a Tour Pack attached to my Street Glide.
This is a great point,,,Just one example from me is the door on the lower fairings, if I leave them opened and pointed at the engine there is less turbulence and it's probably OK to ride like this even in cold weather.