The problem with Paste Effects is it does both audio and video, not either/or. So if I have already color graded my entire movie and I then start using Paste Effects, all my color grading goes out the window for each clip I use Paste Effects on. Or, in reverse, if I do sound first and then want to paste my video FX, I resets the audio. It's deeply flawed to have it paste both audio and video in a pro application, IMHO.
I just tested this using your method where I only copy an audio clip that has no video. What FCP X does is it resets the video to default 0 when pasting effects copied from nothing but an audio clip.
So a feature request would be to be able to paste only AUDIO or only VIDEO or BOTH.
The Logic preset ability is great, however what I'd like to do is be able to set up a Preset for all my Video FX and all my Audio FX. I'm using two or three Logic audio fx on each clip. I need to go through a scroll list for each effect on each clip.
So in one scene of a movie, I may have audio FX of Cathedral, Limiter, AUHighShelfFilter. I have parameters of each of those set for that specific scene. I should be able to save all of those into a preset and call it "Scene 9 at Robb", which is scene 9 and the camera setup that is pointed at the actor Robb. I should be able to select all those clips in that scene that are that setup and then select that preset and have them all get those three audio FX set to those parameters.
I'm editing a feature that has 68 scenes and multiple camera setups per scene.
Being able to copy just the audio or video FX and pasting one of those, versus both, would solve my problem.