Dick, I Don't get it. You say most other modern countries etc etc, well I just had a look at these 2 Wiki pages
https://en.wikipedia.org/wiki/Airspace_class
https://en.wikipedia.org/wiki/Canadian_airspace
Not many places have E, and not many of them have E above a towered Airport unless Primary and Secondary Radar Approach, and, The Canadian C zones go up to FL125
I wonder if our class D regionals would be Class C with Radar App in these O/S systems? That would cost a heap more, and achieve what for us?