Great example of the debate that we should be having, but aren’t generally, because people get stuck up on the basics and miss the bigger picture.
Definitely find calculations of muzzle velocity and potential damage an intriguing approach, would have a different perspective on magazines and trying to go down that path (mainly a horse-left-the-barn thing, not practical in any way to try to round up hundreds of millions of “violation” magazines in circulation, and given that a good steel magazine kept in the right conditions to not rust that can be easily refurbished with new springs could last centuries…).
Regulating under the FFA could certainly be a reasonable approach, that would also require compromise and funding on that side of the house to ensure that the process isn’t an impediment to legitimate ownership.