Yep, the design grew out of the Demon and Banshee and at one stage ( as the F3H-G/H, which
AFAIK only existed as a mock up) it did indeed have a straight T- tail.
I'm not aware of any of the design iterations having a T tail, and they numbered 98B (F3H-G/H) to 98S (F-4 prototype, YF4H-1).
Can you shed some light wiggy?
The WWII Beaufighter sported both a straight tailplane, and one with dihedral, depending on mod status. As the pilot notes state, "There are a number of aircraft which have not yet been fitted with a dihedral tailplane. These aircraft will be found to be considerably unstable fore and aft under all conditions of flight and particular care must be taken at the lower speeds and at heavy loads."
Interestingly the pilot notes carry the caution "cloud or night flying is not advisable as handling becomes difficult below 180 m.p.h." Yet the aircraft was used as a night fighter. Have to admire the crews, not only did they have to contend with the enemy, but also their own aircraft.