Not sure what you mean by "layer" its one thing to search and replace the references to crossings, or tracks, but if you need to make adjustments to the terrain, or track titles you will see the number of files grow rapidly.
Then you will get somebody who says, oh wait, that tree is facing the wrong way, I need to fix that. In each of the scenery tiles. Can you see where I am going with this?
If you are not concerned then, go for it, but you may want to read about how Styckx was so gently handed by RSC when he tried to do a good honest deed.