I watched the video and you yourself confirmed my words.
For fine tuning, the use of curves is appropriate. But I don't need fine tuning. I'm talking about making a ladder offset by selecting the bones and specifying a offset of 5 frames for example. One simple action to select all values. One simple action specifying the number of offset frames. One simple click action apply.
By the way, the video shows that it is difficult for you to set the offset when dragging the frame value to a new frame. So it's hard for me too.
