Certainly does seem flow well enough, that hole is in one of the oilways... The temp was always 'normal' for a standard engine. Even out on track for 50 mins without coming in and it was the same temp as when I first went out... If it wasnt not flowing, the pressure gauge I had wouldn't have been showing a reading based on revs increasing/decreasing... If the oil pressure rises and is forcing down that oilway into the hole, it will be pushing more oil in forcing some out at the same time surely.
I left the sensor out the end of the t-piece once by accident and it shot out miles in front of the car the instant the engine started - so once the oil hits a sensor it would flow the opposite way, not just stop dead in its tracks? Does not really matter for me anymore anyway, as I dont even run that setup now. I couldnt be arsed with gauges - standard F4R engine does not need them IMO.