Hiya
A neat idea, but I can forsee a couple of problem area’s
Railway track is very rarely constant radius, the transition is invariably a bezier curve, it might not be a problem depending on what you are after in the final product.
You could set bogie rotation via this method ( although the transitions would need some refining) but you also need to calculate the lateral offset.
The centre of the bogie is not over the centre line of the curve (again it is probably fine with a short wheelbase and genorous curves )
So far all rail related simulations (as far as I know) do calculate that the bogie centre is on the centre line (spline) if you introduce the offset it makes calculating the position of the second bogie horrendous.
This was far beyond the scope of my simple mathematics, hence I have explored the physics option.
Only my thoughts but hope of some value
Paul_G