I assume you mean the disadvantage that History recordings aren't updated in the viewportdisplay when the animation is previewed (“played”).
Indeed many times I had to write: “You can get a (bit shaky) Preview though by pressing and holding down left mouse button (not clicking) the small right/left arrow buttons of the timeline slider.
As I understand from the developers it has to do with the corporation between Rhino and its plugin Bongo. Switching in-between to update the History would seriously jeopardize the preview. I agree research needs to be done. Obviously to far-reaching for a Service Release though.