Turtle, knew that but stayed out of the all too common should I use premium or not...
Admit that am not as up to speed on DI as could be and will bone up on your link later
Also know you know this stuff, so academic for you and discussing for others
In order to gain as much PSI on the piston tops, ignition timing has always been before TDC...AKA advanced timing...this also now has DI squirt before that ignition spark, as the fuel has to be in there before the spark
This discussion started out, for me, on the intake valve getting fuel to carbon up on the manifold side
Overlap is who that fuel gets pushed back into the manifold side of the valve and my point or really a question/comment...why not close it before the fuel squirt?