% based damage or healing likely should have different rules for bosses or elite enemies.

Currently, burning ground / foul ground apply equally to all targets. This creates a problem because it means any long fight can quickly become impossible because a monster walks across multiple tiles of foul ground (especially since they leave foul ground behind by movement) or trivialized by applying burning ground and then knocking enemies through it.

This is doubly problematic given one of the summons casts burning ground - which, combined with Shriek - or something echo'ing - rapidly trivializes any amount of hp soak.

The fact that this is rewarding / punishing isn't the real issue - but likely that the payoff amounts should be different for "normal" small fry enemies and larger "kind of a big deal" enemies. Perhaps % based damage or healing becomes less effective with neural enhance level - as the large amount of HP bloat in neural enhancements greatly magnifies the above issue.