The DET3 is capable of driving up to 8 injectors directly (up to 4 per output channel). Most customers just use the DET3 to modify the MAF or MAP sensor signal, as you have to start from scratch building a fuel map when using the DET3 in "fuel implant" mode.
If your factory rev limiter is fuel only, then yes, you should be able to raise the rev limit when using the DET3 in fuel implant mode.