Setting supersampling in the Oculus app has no effect. vorpX works quite a bit different compared to native VR apps. First the game gets rendered at its own resolution, then in a second step vorpX sends the image to the headset. The supersampling set in the Oculus app would theoretically affect the second step, but actually doesn’t since vorpX figures out a suitable resolution for the second step based on the game resolution.
Long story short: all you have to to care about is the game resolution. The higher you set the game res the better quality wise, but obviously you have to keep an eye on performance. Your 1832×1920 are fairly high already.