We bought some of these along time back. We never had a problem with them other than not liking them as much as a regular dive mask. Ours were name brand that costed about $70 about 15+ years ago. The newer full face snorkel masks sold at Walmart and Amazon are really cheap junk. That being said, so are most of the regular snorkel masks at Walmart and Amazon.
The full face snorkel mask is a good product for a short top water snorkel, imo. It's definitely not as good as a regular snorkel set up but it isn't meant to be, imo. Full face snorkel masks are not for anything other than a short top water snorkel. They aren't for swimming. They aren't for diving. Oddly, they were popular during covid as a safety mask as you could install a k95 filter over the snorkel with no reported deaths or co2 concerns.
Anecdotal statements and a study with 20 participants isn't enough evidence to actually ban a product. Using this as an explanation for Maui having a higher death count of tourists that snorkel is bogus, imo. The reason so many more tourist drown in Maui has more to do with the age and physical condition of the tourist, imo.
Bill