JimmyP I’ve already told you that higher alkalinity in brew water attenuates perceived acidity and contributes to body and less clear flavour definition. This is well understood in the beverage industry, not specific to coffee.
The effect on perceived acidity assumes that the acidity/acidic notes in the coffee in question is not due to under-extraction.
You can also brew with distilled water (for brewed & with your Flair - not with a machine with a boiler) then add total hardness & alkalinity to the brew with drops, like Lotus drops to see the effect.