Thanks for your willingness to help.
It is not possible to import an exported morph target into UE4. It will error:
FAILED TO MERGE BONES:
This could happen if significant hierarchical change has been made
- i.e. inserting bone between nodes
Would you like to regenerate Skeleton from this mesh?
***WARNING: THIS WILL REQUIRE RECOMPRESS ALL ANIMATION DATA AND POTENTIALLY INVALIDATE***
If ‘yes’, it will want to add the morph targets as if they were bones, and that is obviously a bad thing.
Edit:
The documentation says to export the base mesh + skeleton. You say to export the morph target. Neither work.
You say to animate the morph target, the documentation doesn’t.
There needs to be a clear guide on this because whatever the process is, it isn’t transparent.
Edit2:
You do not say to bake the animation in your listed steps either, or to tell the exporter to, but then you later refer to the baked animation. Not that baking it or not makes any difference.