Grooving lifter bores

This question is for anyone familiar with the process of adding grooves to the lifter bores for the purpose of improving lubrication to the lobes on a flat tappet cam.
I am using the Comp Cams lifter bore grooving tool and in their instructions they say that for best results, the groves should be on the inboard side of the driver's side of the block and on the outboard side of the passenger's side (left hand drive), based on clockwise cam rotation. This makes sense to me on the passenger side, because the groove will line up with the oil gallery, but on the driver side the gallery is outboard and the groove will be on the opposite side of the bore. Am I wrong to think that the groove on the driver side would work better on the oil gallery side?
I called Comp cams Tech line and the guy knew nothing about the tool or Mopars, he just read the instructions back to me.
Don't bother suggesting a roller cam, this engine will use flat tappets.