Even better how about GLOBAL REGULATIONS full stop
Good grief! Please NO - I have enough trouble keeping up with all the EASA nonsense.
Don't get me wrong I'm not against better standardisation but you're never going to have a one size fits all. Part of pilot training and operation is management of altimeters etc.
Perhaps we should recall that all of us in the UK now have to suffer the imposition of having to say "Hectopascals" whenever the pressure is 999 or less because a couple of US operated aircraft confused inches with millibars (as they were then) and ended up with at least one potential CFIT at Birmingham (UK). We also have to suffer the nanny State stuff on the NOTAMs when the pressure is low reminding pilots how to set their altimeters.
Be careful when you fix one problem that you don't generate a load more.
When in Rome do as the Romans.