My ISTP can use Fe very well in response to stress, as long as the stress involves other people, particularly people he cares about, as long as he doesn't feel directly angry or agitated for himself. His Fe can really suck, but like if you mess with his mommy or someone he cares about, he'll be there to jump over the fence and beat your ass in about two seconds. Of course that also involves Se. A more particular "NFJ-ish" example would be when he goes into "counselor" mode, and is totally chill while other people are freaking out, and he explains why everyone else should calm down, and what might produce a win-win situation.
I thought he might possibly be an ESTP at first, like just a very reserved one, because of his Fe, but his mother is an ESFJ so he's tapped into it because of that, and it's really not as good as it first appears to be. If he gets his own personal feelings of anger or anxiety involved, his Fe turns to absolute dust, like it doesn't even exist. Instead of being a counselor, he becomes a terse, abrupt jerk.
He's still pretty young, though.
Still, he has concerns, like what his family will think about this or that, he tends to want to keep things private, and I think that might have to do with his inferior Fe, for all of his kind of quiet lone wolf insolence he does actually care what certain people think.