CocolinoFan
Yep I just confirmed with the Discord mods. We do option 1) removed from OSM and add it to OHM. Not gonna lie, it hurts a bit removing things.
Now I've done the work removing the rail but not committed yet, I don't want to be the one to add the rail to OHM >..< The OHM map is incomplete so is hard and also I would need to find exactly when the rail was built and when it was decommissioned. That's a bit too much work. I guess the rail lines will stay on the map for a while.