bones could be implemented in POFs now, simply have the skeleton as a set of subobjects with no geometry and some sort of property flag in the skeleton base. would have the advantage that all animation code would be unified (i.e. things like turret animations would work out of the box). there are a couple of ways you could organize it, skeleton as child of skin, skin as child of skeleton, both being siblings to a common null base. point being you wouldn't need to make any changes to the POF file format or PCS2 (other than possibly file conversion), you would just need to add support in engine and maybe in the converter.