If you see carbon tracking or “flashover” on a spark plug, boot or coil, it is not normal.
The perfect internal combustion engine would put the exact amount of fuel and air into the combustion chamber.
No matter if it is the secondary or primary side of the coil, inspecting the grounds should be one of the first tests.
A coil takes a finite amount of time to build up this charge. This is the dwell time, normally defined as the camshaft’s degree of rotation, during which the voltage flows through and charges the primary side of the coil.
All ignition coils transform a low-voltage/high-current power in the primary to high-voltage/low-current energy in the secondary.