Stealth and Drop Tanks

One of the reason 5th generation fighters are so big is the need for large internal fuel tanks. While F-22 can carry drop tanks for certain missions, its low RCS is compromised even after the tanks are dropped due to the pylons. Why can’t some kind of retractable pylon be included as an integral part of a 5th generation fighter design? That way drop tanks can be used on a regular basis. The airframe can be smaller, more optimized for performance.