All I know about the .fbx file format is that there have been different versions over the years and the different softwares which can import it may or may not do so with issues.

I use the format to export/import whole objects with rigging, textures and animation. I can export such a file from Reallusion's Character Creator and it works perfectly imported to Carrara (apart from texture tweaking being required) but it imports with big problems to Poser - the animation gets messed up.

Please excuse me if I'm not around for much longer - I generally don't get to posting until the end of the day.

The soft-body settings I spoke about above for stiffness and bending - with self-collision on - are really about all I used.

If you want to drape garments then making your own, very simplified meshes might work better than bought PA items. Try a well-tessellated flat disc with a hole in the middle to clear the figure's head and see how it falls over the shoulders and drapes into a poncho.

I often used to try fitting a kind of baggy vest made from a cylinder. The vest from just above the waist ended as a wide flat (or slightly sloping) disc - like a ballerina's tutu. I would paint soft-body-attach vertices where the base of the vest became a disc and maybe a few under the bust. You can create the beginnings of interesting garments and tunics from the resulting drapes.

If you try with a disc only to make a poncho, the mesh will be much like a flat spider's web with a hole in the middle. Try deleting some of the edge-loops within the 'web' so that a loop of faces is twice the size of the others and note how these faces stretch more in the simulation. Or else add in a few loops to tighten the drape at that point.

Try taking your disc and tilt it at an angle before simulating and see how that works.

I wasted way too much of my time with all this in the past (wasted because Carrara's Bullet Physics is incomplete or flawed) but it has helped me enormously with getting to grips with other solutions when I tried. I haven't even looked at Dforce but I imagine I'd have a head start in getting to grips with it from Carrara experiments. But, who knows? I might be wrong there.

Edited for clarification.