Most crankshafts have one or multiple critical speeds which need to be pushed through as rapidly as possible to avoid crankshaft damage. On the old nissan L28 it has two, one around 6200 rpm and iirc one around 6700rpm. If the crank is held at these speeds for any extended period of time, the engine life is drastically reduced.

Just because the engine is balanced does not mean it does not need a damper. I can only think of a few instances where the engines are run without a damper, and none of those engines are designed to last very long, just put out gobs of power and live short, violent lives.

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1993 190E 2.6 Sportline