Environment issue/ Wake Vortex Relevance
Area Control separation standards are not affected to anything like the same degree as Terminal/Approach Control, where Radar separation standards can be less than "Area", and runway utilisation demands critical spacing.
If the air at high level is fairly still. I am always aware of possible in-trail turbulence behind a "heavy" and will control accordingly with consideration ....but that is a result of experience rather than teaching.
Before "Heavy", the suffix was "Vortex".
When the early wide-bodies were introduced it was evident that wake vortex category defined purely in weight terms was not always prudent. This lead to certain grey-area types being re-classified as a result of their individual characteristics....in some cases different States use their own unique categories.