Fe valuers value controlling emotions to express them in a socially recognizable manner I believe.

It’s not that they are less emotional, but they are more attuned to social markers and oriented towards catering towards emotional expression that uses them. They are probably more thorough at seeming more rational and cold/calculating than Fi valuers are because of this. But as others have said, some EIEs and such (any Fe valuing type really) can have explosions that are a result of a lack of emotional awareness too, and Fi valuers can stay calm and cool also.