don't let the shaking bother you, the plane can take it.
In such a situation my main worry would be that the engine would tear itself off its engine mount. Is there a formal certification requirement or something that would require the mount to be strong enough for an unbalanced engine running on all minus one cylinders, either through a stuck valve or blown-out spark plug, at full throttle?
On a lighter note, I can confirm from experience that a first-generation Alfa Romeo 145, with the flat-four 1.4 engine and two distribution belts, can continue running on two cylinders when one of the distribution belts breaks. Lots of shaking and a maximum of 60 km/h, but it got me to a garage. (The same garage who was responsible for installing the distribution belt wrongly in the first place, leading to its failure after only 16.000 km.)