It never mentions that 2x4” lumber is being used. I assume that’s the case. The shopping list/cut list would minimally hint toward that.
It doesn’t state you are building it on its side, which I once again am assuming from the diagrams.
Additionally, I’ve never seen stated anywhere (in the stand building instructions) the need (design goal) of the slanted stand. Once again my assumption, would be something along the lines of:
The goal of the slope is to allow the weight of the sled to apply pressure to the cutting surface. The exact slope is not important, as long as that goal is met. It’s preferable that both sides be nearly identical to keep the geometries simple. Too much slope will negatively effect the tensioning of the chain that is moving the router.
I’m sorry for the confusion too. I am in the process of writing the assembly instructions which is why the page is a bit of a mess. There will soon be step by step instructions on BOTH of those pages instead of just the one.