I do not think you can mess with that one tho. I think it might be needed part to the game. Although I have not looked into it with great detail.
When you enter a system you can still scan without alerting the reapers. However, if you use your scan too many times the reapers will be alerted. There is a bar on the bottom of the screen that shows how much the reapers are alert to your presence. When the bar fills up they enter the system.
If there's a physical display as to how much attention you're drawing, that would seem to indicate there's a value behind it which can be manipulated.
The problem will be whether or not that value is attached to the actual amount or just purely visual. I remember trying to create a trainer using values on screen, but it never worked because, for example, the health displayed on screen wasn't actually attached to the health value.
Yes, normally that's correct, but on some occasions I've been unable to find the value even using that method.
Of course, Cal uses far more advanced techniques of finding values than searching for them like beginners such as myself.