I am using 3DS for my 3D graphics and recently ran into the problem that it’s morpher modifier only allows for 100 morph targets. If you want to do a customizable character, that may not be enough. The manual states in FBX/Morph section this:
The FBX morph target import pipeline allows for importing both a SkeletalMesh and morph target all at once, or importing one or the other individually.
but I couldn’t find a way to do it
So I would wish for a way to add morph targets to an existing mesh by importing it from second FBX file, which must contain the identical basic mesh and skeleton of course.