I've done a load of ScaleRail "replacements" in MSTS, and wondered if this could be accomplished (though, never found enough time to delve into the technicalities--the where and what within the XML that needs to be found and replaced)
Actually, it's quite easy. All you have to mess with is the tracks.bin file. You use Serz to convert it to XML, then replace the references to the tracks and switchstands in the file. In my case, there were close to 5,000 references, and the signals complicated things a bit. Track height before and after Scale-Rails was not an issue - I built the mainline 3 feet off the ground to begin with, as i've never seen railroad tracks on a main that sat flat on the ground (FUTURE RAILROAD SIMULATOR DEVELOPERS PLEASE TAKE NOTE OF THAT FACT!).
It's a must-do conversion! ScaleRail will probably be my first purchased add-on for RW.