Both compression and redline need to be raised. And it just so happens that they both start at a similar looking number.compression or RPM? You are being very confusing now. But I doubt it would have a problem keeping up.
Raising compression actually requires the same amount of fueling but makes a stronger burn.
The stock compression ration of the CBR250 is 10.7 to 1.
The stock redline of the CBR250 is 10.5k rpm.
The compression on more serious bikes is around 12.5 to 1 or 13 to 1. This is the case with the CBR1000rr which shares the cylinder specs with the 250r.
The redline on more serious bikes is around 12.5k to 15k rpm. This is also the case with the CBR1000rr.
To make power on the 250, given that it shares the geometry and valve specs as the 1000rr, it is logical to match areas that are decreased to the 1000rr's stock specs, thus raising the compression and redline to the 1000rr's stock numbers.
Both an increase in redline as well as an increase in compression require more fuel, as does any other way of increasing power. An internal combustion engine is just an air-pump. That is what it boils down to, it pumps air expanding by an explosion. More power means more force, caused by a larger explosion, needing more air, and thus more fuel, keeping in a proper ratio. The same is the case with forced induction as it is with high compression, more air going in means more fuel required, and thus, a larger injector is required after a certain threshold.
And if you don't need the additional injector capacity, the larger injector won't hurt the engine as would be the case if you needed a larger one and had a smaller one instead. It is just a safety precaution.