I can’t say for sure which FT plane has the longest flight time.
I agree with
@JasonK, there are many factors other the design of the plane that affect flight time. I can fly my Versa for 6 minutes, throttle wide open. It will fly for 15 minutes using throttle management. With thermals, I’ve flown for 30 minutes. All with the same plane, motor, prop & battery. My current setup is for speed, I’m sure I could get longer flight time with a different prop & motor.