Currently if you build a train track going up a slope that was excavated or filled using designations, you can only match that to the 25 degree grade option, which is less efficient for the trains. Naturally you want to limit the train to the 12 degree option. But this means having a ramp that is not parallel to the ground and quickly ends up being too big of a gap for supports, so you have to build in flat parts to the terrain so the train ramp can "catch up" to cover a greater height at the lower grade.
This suggestion is to allow us to have a second grade option (12.5 instead of 25) that matches perfectly with the less steep train grade, making for more consistent and easier to plan layouts.
The attached image shows that getting a track up 16 tiles in height, you need 32 tiles in width, but have to spread out the slope in the middle in order for the supports to reach.
