An Aerodynamic lid is of no use in an area of turbulence. There is no air flow to be dynamic in. And well fitting whilst it will reduce the noise associated also means your head moves more. Even so a well fitting helmet SHOULD be the choice. You are basically driving with a barn door at near vertical face on and it will generate turbulence. End of Story.
Also note that FULL FACE helmets seem to waggle more - but in reality it is because your head is inside a sound chamber that allows you to notice the associated noise. Open lids (or no lid) you wont hear it but it still happens. A light helmet allows your neck muscles to control the waggle with more ease. The weight thing really matters far more than you'd think.
I have tried Triumph lowers, raising the screen, venting the screen, changing teh screen angle, a screen aerofoil (LaminarLip), my current fork mounted lowers, engine bar mounted lowers and pretty much every combination. Tried mounting at an angle or square on - all sorts. They will all affect the effects of turbulence to some extent BUT not always at the speed you want to ride. Also affected to where YOU sit related to the screen. So riding position.
My current combo is fine to 130-140kph depending on whether there is a crosswind of any reasonable magnitude or not. Then gets a bit rough and then smooths out again above 170kph. This I like as it a sort of passive speed alert system on longer runs.
For an INDICATION of head shapes and Helmet shapes - webbikeworld is a brilliant reference.