I overheard ahzi talk about the ramps on octagon so I decided to see what was going on. There are 3 different elevations.

Starting from the center of the 'octagon' and moving outward you have the lowest elevation until you walk up a few steps. The end of the "low" elevation is shown by the red lines. Then there is a narrow strip of "medium" elevation in between the red and black lines. Then there is a slightly bigger strip of "high" elevation which is only the area inside the black lines. As you walk down the steps you once again have medium elevation.

The top 2 ramps (NE & NW) operate how you would assume with the gray area actually being the high ground, but for the bottom 2 ramps (SE & SW) the high ground is actually in the middle/top of the stairs. While the lines might look carelessly drawn I put in effort to make them as accurate as I could, especially the bottom ramps. The borders just look like that. The top ramps may not be quite as accurate because I got frustrated since the elevation borders didn't follow straight lines as cleanly as the bottom ramps and I had already spent a lot of time on this.