The following reads exactly the same on regular Edge and EP which makes it sound like the primary difference is simply additional additives targeted at longer drains.
Improves oil film strength by 30% and reduces power-robbing friction
Ten times stronger against high temperature oil thickening to unlock maximum performance*
Six times stronger against wear vs the industry benchmark**
Improves fuel economy (0W grades)
CASTROL EDGE IS 3X STRONGER THAN THE LEADING FULL SYNTHETIC AGAINST VISCOSITY BREAKDOWN***
I'm simply trying to figure out if EP has any advantage at lower drain intervals.