Take a look at pages 6 and 7 in particular:https://www.webcitation.org/5nhOeXhRQ?url=http://www.jensen-transformers.com/an/generic%20seminar.pdf
"In the professional audio and video fields, the cheater plug has been identified as a serious safety problem. Its casual use as a method for avoiding ground loops in analog audio and video signals (to eliminate hums and buzzes) is dangerous.Bill Whitlock, president of Jensen Transformers, writes, "never, ever use devices such as 3 to 2-prong AC plug adapters, a.k.a. ’ground lifters’, to solve a noise problem!" Whitlock relates how an electrical fault in one device that is connected to its electricity source through an ungrounded cheater plug will result in dangerous, high current flowing through audio or video cables. Whitlock notes that in 1997, consumer audio and video equipment electrocuted nine people."
Even PS Audio recommends using a HumX to safely lift a ground. They state "It is not recommended to run your equipment ungrounded, for safety reasons."
https://www.psaudio.com/ps_how/how-to-find-and-fix-hum/