Discussion on alternative sources for MOND-like phenomenology?

Hi r/Physics,

I was hoping to start a technical discussion on MOND-like alternatives to Dark Matter.

While most MOND-type theories modify the gravitational action or kinetic terms for matter, I'm curious about the viability of sourcing the acceleration discrepancy from a different mechanism.

What if the MOND phenomenology (i.e., the Radial Acceleration Relation where a_eff^2 ≈ a_N^2 + a_N*a_0) arises from a new vector field that couples directly to the baryonic angular momentum tensor?

I'm trying to map out the theoretical landscape for this concept and wanted to ask:

1. What are the biggest theoretical or observational "showstoppers" for this idea?
2. Would such a coupling to the spin tensor already be ruled out by solar system tests (like planetary perihelion precession or LAGEOS data)?
3. How would this kind of vector field affect gravitational lensing observations compared to standard MOND or Lambda-CDM?

Are there any key papers or major constraints I might be overlooking? I'm trying to understand if this concept is a non-starter from the beginning.

Thanks!