Quote Originally Posted by Scott Bernstein View Post
Yeah…I suppose I should say “consistent with code”…or “NEC-style” installation.

Yes my worry is that having an installation in which two devices could exceed the amperage of the circuit would not be in the spirit of the code. Hence the idea for the switch. In the end I just went with a flexible cord installation for the heater, plugged into a 50amp outlet. That way only one machine will be on the circuit at a time.
As long as the correct breaker is used for the gauge of wire, the branch circuit is protected. Whatever that is wired/plugged into the circuit may not be protected.