I discovered something today that I never noticed before. While using the animation tab, If you want to set a keyframe for the current transform position/rotation/scale on multiple objects that have varying values: With Record enabled, select them all in the hierarchy then right click on Transform in the inspector. A context menu appears with key options, click "add key" and they will all be added. Also, you can unfold the hierarchy entirely by pressing alt-right arrow. These may be obvious to some people but I never noticed it before. Enjoy!