Speed will probably not be an issue once I get the simulation ported to C. We’ll see 
Skirts and capes are on the expected to-do list. They are a bit trickier than hair for two reasons. First, they need a different kind of physics primitive, as they are two-dimensional.
The question of how to create a suitable physics model for this case requires some thought. If the rod lengths are fixed in both directions, the range of possible motions “locks” in an undesirable way. One possibility is a discrete approximation of an elastic sheet, built out of point masses and springs. I’ll have to think about this.
Secondly, the two-dimensional nature makes them trickier to configure in the modelling package than hair, because the horizontal connections between neighboring joint chains cannot be represented in the armature. It might be possible to encode the horizontal connections via a naming scheme for the joints, but that feels hacky.
Anyway, I’ll probably experiment with this, as I’m also interested in having support for physics-enabled clothing.