I think this is a very subjective argument, with so many variables, that there isn’t probably one answer to suit everyone. It depends on expectations and one rider’s idea of excessive buffeting will be entirely different from another’s.
I am Mr Average, (5’10”, 11.5 st), and my 2015 Glee came with the Suzuki accessory ‘touring’ screen with the extra spoiler near the top.
I raised it up to the higher position by accident, when I removed it to clean behind it and put it back higher!
But from new I’ve never noticed any extreme buffeting or excessive wind noise from this set up, based on my idea of what is acceptable.