The arXiv preprint (2605.26217, v1, May 2026) models the HD 20794 system using N-body integrations spanning 10 million years across inclinations from 5° to 90°, confirming long-term stability even when planet d reaches ~67 Earth masses. HZ boundaries were calculated via standard stellar flux limits, showing the ~5.82 Earth-mass planet spends a quantified fraction of its 0.45-eccentricity orbit inside both conservative and optimistic zones. This work correctly identifies d as the lowest-mass confirmed world with e>0.4 whose periastron crosses the HZ, positioning it as a potential dynamical disruptor for any additional terrestrial bodies. What the analysis underplays is the extreme seasonal forcing: periastron insolation spikes could drive atmospheric escape or surface temperature swings exceeding 100 K, analogous to but far more severe than Milankovitch cycles on Earth. Secular eccentricity oscillations follow Laplace-Lagrange eigenperiods that shorten with higher system mass, implying that undetected outer companions could pump d's eccentricity via secular resonance—a mechanism also invoked in studies of the upsilon Andromedae system (Ford et al., 2008, AJ). This connects directly to astrobiology target selection for the Habitable Worlds Observatory, where orbital variability must be folded into climate models rather than treated as static HZ occupancy. Limitations include reliance on minimum masses, the assumption of no additional planets, and the short 10 Myr integration relative to the star's multi-Gyr age. The preprint status means peer review may refine these stability conclusions. Overall, HD 20794 illustrates how dynamical architecture filters which worlds merit atmospheric characterization.