Would love if we could set up global ease curves directly in the sequence by right clicking a keyframe and setting a curve for it (more detailed than existing types), without having to go to the curve editor and tweak every single axis and rotation. With one global ease curve, all of them together would be affected, which would speed up the process since that is the most common use case for curves (rarely you want different curves for different axis, but even if you want that, the existing functionality would help with that).
OR
The ability to save a curve and apply it to keyframes afterwards