I had this problem in a Cessna 182. TCM used airmelt forged crankshafts, and the "Perfect Storm" RPM, the one that resulted in harmonic resonance, was 2250 RPM, which was right in the engine's sweetspot for optimum cruise. The airmelt process (as opposed to the vacuum melt process) left impurities in the forging, which resulted in weak spots.

There was no dampening of the crank, and the one in my co-owned airplane snapped. While my a/c partner was flying. At 7,000 feet. At night. In the clouds.

Luckily, the crank split across a facing, and it did not fly apart, taking the propeller with it. Bill glided down to a convenient airport and landed safely with no power.

There were several similar failures, and TCM eventually did an FAA mandated recall.

A split crank is not as dangerous in a car, but it is inconvenient and expensive, so I'd stick with the Volvo engineering on this one.