Jim,

Yes, engine roughness is caused by one cylinder misfiring.

Not at all. Or rather: very rarely. Engine roughness which we normally
encounter during leaning is caused by the cylinders developing
different amounts of power.

Fuel injection is properly calibrated is the same on all
cylinders so the engine runs smooth and balanced.

TCM and Lycoming specs don't at all require that. Which is why
GAMIjectors are such a success. And no, GAMIjectors DON'T calibrate
fuel flow to be the same for each cylinder, since you don't want or
need that. What you need is the same fuel-air ratio in each cylinder.
So those cylinders that get less air need less fuel, too.

Read Deakin, it's all in there.

--
Thomas Borchert (EDDH)