Even if the process allows, the T effectively does “routing” in active-diff: usually not best. All src/drn area & perim contributes diode parasitics (cap & leakage). In typical stick diagram of nor2 layout, the output is tied to the (smaller) shared src/drn between the two nfets, relegating power to the outer src/drns: i.e. avoid added diff-perim where it slows down active signals.