My elegance is brutal as well! It's surrounded by a wall of astrea snail shells. Nothing enjoys escargot as much as this thing does!
I passed my arm too close to it one day while working in the tank, and it latched onto me so hard that when I pulled my hand back, it lifted right off the sandbed, stuck to me! I feed this thing every week as well! Hopefully it's not developing a taste for people...
Bummer on the Sea Hare. I would try to delicately remove it, that's a lot of animal for an elegance to consume, and it's not worth the risk of fouling the tank.