None ever came installed new/from factory. Austin is right, the FP one's are nice and fit to look like a factory install. Also tons of aftermarket options if you so choose. Driver side not needed unless you're tracking the snot out of it, and even then, I've seen reports it catches minimal oil on rare occasion.
Just installed passenger side -- on the longer tube, videos say 45deg goes on separator 90 deg on engine...found (for a 2020) that the opposite fit up more naturally - do others have the 90 deg on the engine or the separator?
I remember I either reversed/switched the tubes, or reversed the direction of one. Again, as you said, because it fit better.
These seperators are made to go in several different cars, with different engines, which is why it's not always an exact fit when installed. And I found if you warmed the tubes with a hair dryer, it makes bending the tubes easier without kinking them.
I have seen a bit of oil in the driver one I had on my first gt350 after a day at the track where I really pushed it. I’m putting both sides on my latest GT350 to cover the track days