The track length shown will not alter whether you are using Offset correction or not. If your drive cannot Overread into Lead-in and Lead-out you will be missing some samples from either the beginning or the end of the CD depending on whether the Offset is positive or negative.
This means, I think, with an Offset of +6 the first track when extracted will be missing 6 samples unless your drive can overread into the lead-in.
Please remember that the CD is sampled at 44100 samples per second so 6 samples would give a time difference of 0.00.00.000136 which is too small to show on the comparison result.
Really an offset of +6 is so small that I wouldn't worry about it. If it doesn't work properly then just leave it at 0.