Please explain this as the filter doesn't return any oil.
The oil is pumped into the filter through those holes and out to the engine through the center fitting that the filter screws on to. It simply passes through the filter from the pump into the oil passages in the engine. You did increase the volume of oil available to the filter but one has to wonder if the outlet fitting is capable of flowing the extra oil. Not to mention the filter or the passages on the pump side.
I did the same mod to my adapter plate when I ran it. :thumbsup: