I stopped buying neoprene pouches. They were so flimsy that they didn't provide much impact protection.
I have the Ape Case ACPROLC18. With the lens retracted and locked, the case will also fit the lens with a body mounted. It's a tight fit like that, and the lid doesn't fully seal, but the latch will close and I've carried the lens+body like that many times without issue. Without a body attached, the bag is a bit too big for the lens, and I stuff in an old t-shirt to secure it.