I've never heard of it, and I've been paying close attention to dive accident reports for 13 years now.Re mask around the neck concept, I've heard a story of a diver who suffered a broken neck when a large wave hit the boat he was standing on with his mask under his chin and his head hit the upper deck. I wonder, if this was a true story or an urban legend.
I used to wear it around my neck. I stopped doing it when I started wearing a bungeed alternate and there was no longer any room for it there. If I didn't have a bungeed alternate, it would be around my neck again.