Regular Six-Throat Spacetime Beyond Singular Endpoints: Exact Transport, Optical Return, and Critical Diversity

We establish that a regular six throat spacetime can support nontrivial transport and optical dynamics while maintaining finite curvature throughout the throat structure. The geometry contains six equal radius throats, arranged as three on each directed branch, with a common minimum areal radius but with different local geometric strengths.Covariant rest mass conservation produces exact stationary fluxes for each branch, and the ultrastatic timelike sector provides a conservative transport benchmark through the ordered throat sequence. In the null sector, all six throats share one universal transmission threshold. Rays below this threshold can cross the complete sequence, while a distinct family launched from the Zero Region enters a return sector generated entirely by the geometry.These returning rays reach an ordinary turning point where the radial motion reverses along the same null geodesic. No singular endpoint, reflecting wall or imposed boundary is required. Near the critical regime, both angular winding and travel time grow logarithmically. The three throat families remain locally distinct, with response coefficients equal to 1 over 48, 1 over 60 and 1 over 240.The returned image family is described by an exact affine visibility transformation. The paper also applies a reproducible sampling audit to public 2017 Event Horizon Telescope data for Sagittarius A*. The tested subset contains 794 cross scale samples from CASA and HOPS reductions. Under the strict simultaneous common support requirement, the matched control count is zero in every tested group, so the corresponding strict matched estimator cannot be constructed from the available subset.The results show that finite curvature, conserved transport, complete null transmission, geometry generated optical return and locally diverse critical behavior can coexist within one regular six throat spacetime. The transport and return mechanisms proceed through regular geometry and do not require singular breakdown as their endpoint.