When the servo-skull is bound to mouse wheel-down you will constantly pull it out and put it away without having any opportunity to use it. I have had no issue with any other grenade ability until now and I have been using this keybind since launch.
Casting this ability is really clunky. On top of that, the medicae servoskull’s functionality leaves me extremely frustrated. It only has a straight-line range of 25 meters, and even the slightest obstacle in the way blocks revives entirely. If I jump down from an elevated platform while my ally gets downed upstairs, there’s nothing I can do to save them. The skull can fly, after all—there’s no reason it should be restricted to a 25-meter unobstructed line of sight. It’s supposed to be an intelligent support drone, not some useless floating object stuck in the top-left corner of my screen blocking my view. It ought to move autonomously like a loyal hound, flying around to heal downed teammates and attack enemies within its radius automatically.
What’s more, reviving allies with the medicae servoskull does not progress any Penance trackers at all. You’ll notice your rescue count never goes up. I revived teammates 17 times in a single mission once, but after finishing the run and returning to the Mourningstar, I checked the Penance menu and my stats hadn’t budged an inch. It’s incredibly disheartening.