The Gear VR use your smartphone screen, not the Rift. That's a resolution of 1440 x 2560 for a Samsung Galaxy S7, which mean 1440 x 1280 per eye. The optic is also made to have more pixel in the center than the border of the viewport. I have no doubt that you can have a resolution similar to VGA with no issue and even better than that if you use a bigger screen. I'm pretty sure none of us had any trouble working in VGA back in the day either.