I made a test with AVSPmod, running FrameSurgeon on the same frame shown above :
The result seems to be more precise than Morph, it deals with moving objects better (that man's legs for instance), with no ghosting effect. I'll try it with problematic frames which I couldn't improve satisfyingly with Morph.
And so, can I safely run a script with hundreds of frame interpolations, with either one of those functions ?