I got rid of the jagged visuals by setting the MobileContentScaleFactor for the device. Create a config file called DefaultDeviceProfiles.ini with the values specified at https://docs.unrealengine.com/latest/INT/Platforms/Mobile/Performance/index.html#mobilecontentscalefactor
https://docs.unrealengine.com/latest/images/Platforms/Mobile/Performance/T_MCF_INI_File.jpg