In this paper, we obtain explicit generation-dependent expressions of six degree-based Sombor-type descriptors such as diminished Sombor (DSO), complementary diminished Sombor (CDSO), reverse Sombor (RSO), reverse elliptic Sombor (RESO), reverse Euler Sombor (REU), and parametric mean Sombor (mSO_α of the polyphenylene dendrimer D_4 [n] The four edge-degree classes are established and induction conditional on the standard dendrimer construction leads to exact edge counts and closed expressions. We obtain power-mean bounds, asymptotic edge proportions, normalised limits, and numerical evaluations. The conclusions are about graph invariants, no physicochemical prediction is made without external data on properties.