That’s exactly what it does 
It lets you select a fixed render scale (rather than auto) and whether you want motion reprojection always on/auto/off.
Most people look to find a balance between the ‘Customised render scale’ in the tool with the render scale in the game itself.
Also gives you the ability to establish and act on how you feel about motion reprojection - do you need the simulated 90fps or are you comfortable with say 30? Reprojection comes at a fairly hefty cost so if you’re lucky you don’t ‘need’ it.
Lots more info here: