I find whenever I use MED with an fbx which has a rigid bound object, the bound object is placed quite far from the joint it is bound to, so a model with geometry bound for legs, arms, etc, are all exploded out. It's very trippy. Also I have found that fbx constraints don't make it in there, but I guess MED only supports models that are plotted to skeleton, instead of exported with a motionbuilder (native fbx app) control rig.