.bone files are chunked with an extra header. They are named "%s_%02d.bone" % (base_name, variant) for models with sequence 808 present.
uint32_t unk; // ignored, shall be 1 (possibly version?)
uint16_t bone_id; // count should be equivalent to number of FacePose (808) sequences - 1
C44Matrixⁱ boneOffsetMatrices; // same count as BIDA, transformation matrix for the given bone