The factory 1992 5.2 injectors were approximately 18 pounds per hour rating at a lower than typical 35 psi
(3 Bar metric pressure or 43.5 psi equivalent is considered standard for rating injectors)

the better idle smoothness would be expected if the air fuel ratio were now richer due to the bigger injector capacity

the better throttle response and seat dyno feel
could also be coming from the richer air/ fuel ratio

over time the OBD-I engine computer will adjust the fuel trim memory positions AFF and AAF to "learn" a leaner air fuel ratio so that the oxygen sensor reports the correct 0.5 volt averaged out value that is "stochiometric"
just a fancy Geek word meaning
just enough oxygen is there to combine with the fuel

the AFF and AAF memories can take hours to adjust
and may not be able to go more than 20% less fuel per squirt

with the bigger Ford injectors you might be able to run E85 fuel

E85 fuel might give a 10 to 20% full throttle horsepower boost.
When Consumer Reports tested flex fuel cars on E85 it typically cut a full second off the 0 to 60 mph time.

E85 fuel might dissolve a lot of gunk out of the tank,
some of which might get caught up on the little protection screens at the top of the Ford fuel injectors

unless the local E85 fuel costs less than 70% of gasoline per gallon you wont save any money per mile driven