I must admit to being at least a little bit irritated that altimeter settings provided by ATC are universally given in inches of mercury (Hg), even though most regions of the world utilize hectopascals (hPa).
Could any of the more technically minded (at least insofar as software programming is concerned) provide some reflection on how difficult it might be to implement a split system, whereby altimeter settings continue to be provided in Hg in North America, but in hPa for the rest of the world?