Oceanic wrote:I’m more interested in how this will affect the bike’s handling.
It won't, well it will but no more than a cm fore/aft with the saddle, a cm or two higher or lower, the weight of the rider, the size of the rider, what they had for breakfast, the kit they're carrying, the pressure in the tyres, the size of the tyres, their riding style, how hard they pedal, how flexible they are, their foot position on the pedal, and no doubt many other things that haven't just sprung to mind.
These bikes are designed for an average that not many people will be, it's very kind of you to be so concerned for others welfare, but if the don't consider they have a problem there's a pretty good chance it's because they don't. They're more likely to have an issue if they set their bike to conform with someone else's ideas rather then what suits them.
I'm also wondering why this apparent problem would exist with an Aheadset but not with a quill stem. You just don't hear it, so it must be about something other than the height of the bars above the headtube.