Ah, you uncover more localities but then on the method level. I think it would not be wise to remove methods from more capable shakers because of architecture design. I can imagine you might want to shake until a temperature is reached, or shake until a procedure is finished.
So you might want to implement it with a Protocol alongside the ShakerBackend ABC just like the _CanLockInternally Protocol , but then CanStartStopShaking is not hidden.