are cut-off wheels on a die grinder unsafe?

• unsafe https://www.nortonabrasives.com/en-us/resources/expertise/cut-wheels-and-die-grinders-dangerous-combination
• maybe safe https://www.reddit.com/r/Tools/comments/1eu5fj6/is_it_safe/
• unsafe https://www.weilerabrasives.com/en/na-articles/best-practices-for-cut-off-wheel-safety-with-a-variety-of-wheel-diameters
• safe, but only for small diameter wheels and only if you're very cautious https://www.garagejournal.com/forum/threads/you-would-put-this-on-die-grinder.19371/

NOTE — Metabo does make a cut-off wheel guard for their die grinders [1] [2] [3]