If you are seeing a differential offset, it should not be because of CMFB, then as you said, by using a DC offset correction circuitry you can get rid of the DC offset (This is what is normally done in the Direct conversion receivers to remove DC propagation).
But if you are seeing a deviation in the output common mode voltage from what you expect it to be, then the gain of the CMFB loop is not enough. By increasing the loop gain of CMFB, you can get closer to the desired common mode output voltage. But increasing the loop gain might affect the stability of the CMFB loop.