For me, worked fine with the stock facial interface even with this option off. With the VR Cover one, I was getting artifacts on the bottom of my vision regardless of the setting (but a much better sweet spot as well, so going back to stock wouldn't be an option). There are no problems in other VR titles with that option applied, it's just the mask in DCS being a bit smaller than what the driver itself filters out it seems. Now if it was black even at MSAA off, wouldn't be a problem either, but it isn't.