@queuedEU
Sorry for the English...
It looks like wonderful.
My old idea, along with this replacing old rail models. Leaving edges rounding poly count is equal, like older, and give edge for rail sole, avoiding the z-playing with the ballast on greater distance. Perhaps possibly give LoD, for example last submodel be, as a simple trapeze.
This is a simple profile a standard UIC60 rail. True, that's height smaller, than original/currently used.