I can change the physics properties of all the objects in my scene at the same time, by selecting them all then hitting ALT when I make changes in the Physics properties. Or I can copy the values of an object onto all others via Object - Rigid Body - Copy from Active. But neither of these will add keyframes of selection properties in the Physics tab. Such as 'Dynamic' or 'Animated'.
If I want an object to drop at a certain keyframe, I can tick the Dynamics setting in the physics tab and keyframe it. But I cannot copy and paste that keyframe to all of the physics properties of all the other objects. I have to laboriously change them one at a time. And I have hundreds!
I've tried adding the keyframe by tapping 'I', but that does not show any relevant options.
If I open the graph editor, I can find the keyframe I added for 'Dynamic' or 'Animated' there, but again, there are no options to copy that keyframe to all the other objects.