I tested an old ray pac commercial, and it has a control box with relays. Now I know that cost is an issue for residences, but we both know a life is worth a little more than a double pole switch. I assumed that engineers would care about the safety at the residential elements.
Would you install a 240 circuit breaker without the connection between handles so that one line would remain hot? I see a sweet deal from UL to the waterheater guys so that they can make them in mexico of tin cans and up the profit so that the "head" of GE can take home a few billion a year. Nice to have 22 vacation homes for the sake of a 6 cent killer switch.
Ethical bankruptcy. Hey: send it to China, then no liability need apply.