Stop spamming Medica I & II/diurnal Aspected Helios

[Rosenstrauch]

So yes, overhealing is a thing.

You misread what he said. "... that generates any more aggro than normal." is the important part of that sentence. He's correct: Overhealing does not have any special modifiers to enmity. A Medica II cast on a fully healed party will generate exactly as much enmity as a Medica II on a party where everyone was dropped to, say, 1 HP.