Isn't that kind of exactly what GPU companies have been doing all the time with game-optimized drivers? And since they cannot just skip work, but merely re-prioritize things, these cheats should be easily detectable by a reduced battery life.
These generally actually make the games you're playing have somewhat better performance (via game-specific hacks). Applying tweaks to a mobile phone benchmark, but then not applying those same tweaks to other apps is just misrepresentation of actual performance.