You can visibly tell the difference if it's working or not, image quality is substancially improved try it yourself and see.
edit: here was an encoder test I did a short time ago today, I'm using 4xMSAA along with 4xSGSSAA (RTX 2080 8gb) at 1920x1080.
P.S: Sparse Grid also works in VR, massively reduces shimmer on textures/edges.