Skipping ahead a couple years here. I've continued to run track days with this small leak which has proven to be very consistent. The back of the engine has been dry so I'm ruling out a head cover gasket issue.

My current thought is the baffle, when installed, was not positioned perfectly and is not allowing a good enough contact between pan and engine. Each time I did the pan install, it was a beast to get the surfaces to meet.

So, this winter's project will be a new oil pan - thinking Canton or Mugen. No oil cooler.

 

Seems case is solved. I installed a new Mugen oil pan (and changed oil) to find another drip coming from near the transmission - but I noticed the oil drips were dirty. After a much deeper dive, I located a small drip on the passenger side of the valve cover that probably worked it's way down to the tray as earlier posters had mentioned. Unfortunately, I had just felt around the rear of the block.

An expensive lesson (new Mugen pan and my time) but it's all good now. Slightly used OEM pan with Moroso baffle now for sale on Ebay.