That’s just for illustration purposes, really.
The installation is pretty flexible actually, you can use an unistrut, a C channel, a “L corner”, or just have your worktop simply overhang and bolt the blocks to the frame
The only constraint is to get the spacers size right for your setup
I’ve seen a mod doing that, but horizontaly (pretty neat mod btw!)
I guess you could double the belt’s length and make a kind of “loop” to get the teeth to face one another, so that it creates a similar “rack and pinion” system
The problem though, is that there’s nothing pressing the Y drive against the side of the table (on the other mod, gravity does that…), and constraining it may hinder the flexibility that’s built-in with the single rail…
EDIT: Found the mod: Modified motion control on Y-axis
Just the default F360 rendering yes