How's facial animation sharing working?…ing/index.html

After reading faicla animation sharing, i have some confuses.​​​​​​:

  1. **“The next thing you will want to do is inside your DCC, bake out your poses to an FBX sequence and import the FBX into UE4. This will give you an Animation Sequence containing each of the curves at their min/max blend values” **.
    if the animation sequence create with morph-based animation, then i got the curves values display under animation editor.
    if the animiation sequence create with skeletal-based animation, then i got nothing in curves table.(what i missing?)

if i understand correctly, the pose asset dirve animation with bones transform. So pose driver animations only make sense with skeletal-based animation. but this make me confuse, other guys say facial animation should driver by morph-bases animation.(otherwise you will got trouble!).
So, what exctly this animation sequence create from?!

if create from morph-based animation, the curve view table, should display all curves as morph curves. But the in doc it looks like custom attr curves;
if create from skeletal-based animation, the curve tables is empty in animation editor. Manual create it? the animtor will unhappy!