This is absolutely essential. The Paste Multiple Keyframes script from Adam Katz will allow you to copy and paste multiple keyframes in After Effects, even from multiple layers at the same time. Check out the Paste Multiple Keyframes script for After Effects on AEScripts.
…This script will let you copy and paste keyframes from multiple layers at the same time…
Simply select all the keyframes that you want to copy, move the CTI to where you want your new keys to be places, and then hit the Paste button.
Adam Katz does note that this script can not work with plugins or effects that have custom values for keyframes. ex.(Levels – Histogram, Hue/Saturation – Channel Range, etc.)
I thought this feature was standard in Adobe AE?? Copy-pasting and alt+dragging the keyframes. Why does the 1st of copy paste in the video duplicate the entire layer and not the keyframes only?