Quote from PhanxSounds like a good candidate for a third-party plugin, but probably too much complexity to add the existing options in the core addon.
I don't understand why this woul dbe of that big complexity. Most checks must already be in the code as they are used by the data filtering (like in groupo, raid, instance, raid instance, battlefield,...). The only exception I see is the boss fight which can be triggered by the unit classification API and checking if in combat. Ok, if one want to be complete one would have to scan the targets of the complete raid for example for healers that may not target the boss. But this might be a separate option as well.