Too little memory can not be solved in sys.txt.
Sorry. It can! By appointing some memory to iGO, but that is device dependable. So there is no general rule. It's a emergency solution, so to speak, and naming the wrong amount of memory can crash the device!
And in general sys.txt should be as short as possible. So that is memory saving after all.
From my experience, I know different solutions that work, however you ...