How To Scale Resolution On Mobile? ("r.ScreenPercentage" and "SetResolutionScaleValue" don't work on mobile)

Hello! I’m developing a mobile VR game and I’m only getting 30 fps so I want to set screen percentage to 70% combined with some antialiasing to gain some fps. I tried using the “execute console command” node with “r.ScreenPercentage 70” with no success. It works in the editor but it doesn’t work on the mobile build.

Other thing i tried is “Get Game User Settings” node followed by “SetResolutionScaleValue”. Of course I didn’t forget to use the “ApplySettings” node after these. Again, it works in the editor but it doesn’t work on the mobile build.

I just need a way to scale the mobile devices’ resolutions down to about 70% of whatever their native resolution is. I am assuming i am forced to use the device profiles. Can someone help me how to do it? Maybe i can insert some lines in a config file to get the job done? Thanks in advance.