Furthermore, the bridge between Carrara and Poser (in this case Transposer) needs to tell Carrara what to do with the dynamic hair first, then Carrara has to figure out how to handle that information at rendertime. Sounds simple enough, but without certain "efficiency" factors in place that only Poser has for it's dynamic hair, it takes a longer time for Carrara to figure out. If Carrara had it's own dynamic hair system, then it could impliment it's own set of efficiency factors to speed up the process (like instancing, or whatever). It's that translation bridge between Poser and Carrara that slows things down. And unlike dynamic cloth, which are usually "solid" mesh objects, dynamic hair consists of thousands of interpolated splines. That's probably also why it won't come in via the native rigging import.