I never used Make Rot From… really, since it does not say what it does and how it works in the documentation, except for the one-liner.
Wouldn’t you need a rotation angle associated with the vector to convert a vector pointing in a direction into a rotator? The vector alone is not enough, right?. But instead you need axis&angle (i.e. vector and ‘screw’ angle) to convert to a rotation matrix.
The whole make rot from thing is another example of stuff that gets coded and implemented, but not documented properly and as such, the majority of users won’t use it. Here we say: ‘then why code it first place’.
Well…the dark and unknown space that is rotations&UE4…