I would normally say support comes from the fit but the sloppiness in the heel would mean support was almost nonexistent so support comes from the Hyperposite especially in the heel area. Even with a sloppy fit in the heel, the Hyperposite is stiff enough to at least keep your ankle from turning more than it should versus a more flexible material or soft heel counter. That being said, I try not to play in shoes wth sloppy heel fits at all since you’re basically allowing your ankle gather momentum inside your shoe to turn over.
Thankfully, the sole is nice, flat and the heel Zoom is firmer to keep the shoe stable overall.