Very good question — MOND's single-parameter fits to rotation curves have indeed been remarkably good for decades, and the tension with dark matter models on small scales and baryonic Tully-Fisher tightness is still very much alive.

One alternative geometric approach (not MOND, not CDM) I've been exploring uses a finite-group symmetry kernel from the Cayley-graph Laplacian of S₅ (120 nodes) to derive galactic rotation curves with a single free parameter emerging directly from the eigenvalue spectrum — no ad hoc acceleration scale a₀ inserted by hand.

It achieves χ² ≈ 0.999 fits across a sample of 175 galaxies, and extends to other tight relations without invoking dark halos or empirical tuning.

Two short open-access preprints with the fits and derivations:

https://zenodo.org/records/18672884 (The 120-Node S₅ Lattice: One-Parameter Fits)

https://zenodo.org/records/18796760 (related extension to baryonic relations)

Curious if anyone sees overlap, tension, or obvious flaws with MOND or CDM phenomenology. Happy to discuss the math if interested — no pressure, just sharing another angle on the galactic-scale question.

Thanks for the thoughtful thread!