AAUI the basic laws can be expressed with dimensionless constants, and in modern physics c is a conversion factor for convenience. I don't know if there's a way to adjust all of the "real" physical constants conjointly which would amount to "just like the Standard Model with a different c".
I want to say it's not incoherent to say e.g. "Newtonian mechanics, but relativistic, with a different c", except of course e.g. Newtonian gravity with its action at a distance doesn't fit, and I wonder if really even contact forces fully work if you try to follow through every detail.
I want to say it's not incoherent to say e.g. "Newtonian mechanics, but relativistic, with a different c", except of course e.g. Newtonian gravity with its action at a distance doesn't fit, and I wonder if really even contact forces fully work if you try to follow through every detail.