This will likely only affect those aircraft that are tied into this for a particular parameter. The example that springs to mind is the altimeter in the C414 which is so would follow whatever setting you have there. Many other aircraft do not tie it in and therefore have it fixed to whatever units the graphics of the gauge are designed for. Changing speed to km/h here is not going to force an airspeed indicator with a scale in mph or knots to suddenly display in km/h. That’s assuming of course that all they’ve done is break out the individual units and not changed the fundamental way things are tied in to the aircraft in fs2020. It’s really dependent on how the aircraft dev sees fit to implement and I’m just fine with that.