Quick update -
While installing my turbo kit I accidentally moved one of the coolant hoses belonging to my forester oil cooler setup and coolant sprayed out. Come to find out there was a pretty big gash in the silicone hose due to the angle. I pulled the hose, cut it and clamped it back up. This led me to believe that was the issue the entire time. So I put the stock part back on in the OP and all was well.
Started up the car with the turbo setup, no leaks. Just got back from a drive with light boost and now there is a little coolant in the same spot under the compressor.
So now I guess I will install the Killer B part when it arrives and hopefully that will be the end of this. I'm scheduled for a built motor E85 tune and may have to do it with the small leak
