Probably not. You could apply some sort of spacing under the "lowest" foot of your PC case. On my 3x1080p monitor setup, I put some cardboard under my 3rd display to even it out, as my desk is not quite "perfectly flat". But your PC case "wobbling" is not intended. Fix it by placing some type of spacer under the "low"/"wobblie" leg, and make sure all "legs" of the PC case are secure and functioning as intended.