I couldn't see what you're using now for a strike plate, but I assume you're using some thin material to get the arrow as far over to the right as possible.
If you can find some material that has some "give" in it to use for your strike plate, like thick fleece or felt, it will cause the arrow to move to the right. You would think that because of the thickness of the material, it would move your arrows to the left, but because of the arrow dynamics compressing the material, it moves the arrows to the right. You mentioned you had tried a carpet rest, and I don't know if you mean you just tried it for your rest or you tried it for your strike plate, but something like that might work.
You could try using an arrow with slightly less diameter shaft, and/or slightly weaker in spine. I know your arrows are bareshafting perfectly now, but adding feathers stiffens the shaft a little, so it doesn't hurt for your bare shafts to show slightly weak, and that will also move the impact to the right.