Not sure if that is actually a solution? No studies have been done yet (I think) which investigate if there's a 'safe' threshold for amount of light the screen

Not sure if that is actually a solution? No studies have been done yet (I think) which investigate if there's a 'safe' threshold for amount of light the screen exposes a person to, under which the effects on sleep etc are absent or extremely small. So for all we know it might be better with f.lux, or the same, can only guess.