So it repeated ” 10-3-5-1 (Failing ignition coils)” again on new coils and new caps ? with new spark plugs?
If you rode on limp mode, was that on 1 cylinder or were both cylinders running okay on your return trip home
It happened to me last week, i found out the front coil had a loose connector which was my fault , i had to change spark plugs & drop the radiator but did not realize the engine vibrates a lot and we have sketchy roads in the UK , so if anything wasnt rtight, it will get vibrated off = Though you have a delphi coil which has a better connector that clips tight, i can’t help wonder if the harness connecting the coils are the problem ?
If no other codes come on the ECU , i am assuming!
Beautify as the GV650 is , I honestly believe it is FARRRRR better to go Carby route then EFi! – I never liked EFi machines (even if it was a Honda etc, too many electronics ,i dont even trust ABS brakes lol!)  == 250cc/125cc EFi owners will have an easier time though as easier to diagnose them