Everywhere else, go JET A! It's cheaper, and it's 'everywhere'
What about Canada, Australia and New Zealand? Avgas rules in these places too.
I'd say the US, South Africa, Canada, Australia, New Zealand and Europe would pretty well cover 90% of GA operations around the world.
So everywhere else is by my estimation is about 10%.
If you start to factor in Adams comments about numbers of airframes that are likely candidates for conversion then the picture for the engine and or STC developer isn't so rosy.
One other question. Does the SMA use a FADEC? If so how is this powered and what battery back up is there? I'd be very nervous flying out over water for longer than the battery could keep the FADEC (if used) powered for.