Interesting! While it’s hard to imagine the stat graph is only for use with dynamic res, that explains what the lines and labels are for.
Frustratingly, even though there are console commands to set the “budget” to what you want, the graph doesn’t seem to update with it, even after enabling dynamic res via blueprint. I am aware that dynamic res isn’t supported on PC, so maybe that has something to do with it. But still, what gives Epic?