No results with inertia vector yet but a couple thoughts occur
-Dynamics is what you are after, can you use Dynamics (soft spring or something), Mocca (I’m thinking the dinosaur tail tutorial here), or a dynamic spline tag with Hair (probably a pain)
-how about faking it? copy the spline that the target object is likely following, paste that and tweek it to fake inertia then attach the camera to that.