MOPED ARMY

Dual plugs don't lead to detonation, detonation is self-combustion of fuel caused by too high temperature or pressure in the cylinder. Mostly fixable by using higher octane fuel or jetting your engine properly.

Alfa-Romeo is also very big on it's twin-spark engines, so the use of dual plugs per cylinder isn't too odd. There's even stock Puch dual-sparkplug heads, but those are rare.