Acceptable Fix for Low Performance (low FPS and input lag)

AcuTarA

My game ran fluidly until a couple of months ago. Now the fps range is between five and 10 and the input lag rises to a full second (In a dash back, for example). I'm on a Samsung Galaxy s7, 20 months old. To try fixing this problem I installed a custom Rom on my galaxy, the Lineage OS. Second to that I installed an app to tweak how the CPU, GPU and RAM behaves in the device. It seemed to do the trick. The game was playable, but for only 3-5 hrs straight, since the overload to the system made it overheat. The Galaxy s7 is a wonderful piece of machine, and I've played in devices 5 years older than mine and 2x the use, and it's perplexing: The game runs amazingly smooth on these lower spec older devices. Full 30-60 fps 0 input lag.
I was investigating about GLTools.https://play.google.com/store/apps/details?id=com.n0n3m4.gltools 
This app lowers the resolution at which the game is played, lowers the textures too and a bunch of other tweaks, just to improve performance. I don't know if it's considered Modding or Hacking or against the ToS in any way. I'm very desperate because I remember how fluid and responsive was the game once upon a time. Any suggestions, any tips, anyone with similar problems, input about the posible ToS violation with GLTools? 
Thanks 
AcuTarA 

Apocalypse189

The lag is really noticeable at the start of the game and lasts up to 2-3 minutes

Somethingsome

Try playing with your phone on top of an ice pack. It's a metal body so the heat transfer will work great on keeping the phone from hitting the temperature threshold. Of course, if kabam programmed the game appropriately for android, they would have ensured it didn't cause such a strain on the device to make it reach that threshold, but they obviously don't care and have no incentive to address it. They're still making money.